Bump version to 2.6.0 (#5820)

*Motivation*

Bump the development version to 2.6.0-SNAPSHOT
diff --git a/pulsar-client-kafka-compat/pom.xml b/pulsar-client-kafka-compat/pom.xml
index 5e0e896..791b033 100644
--- a/pulsar-client-kafka-compat/pom.xml
+++ b/pulsar-client-kafka-compat/pom.xml
@@ -27,7 +27,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-client-kafka-compat/pulsar-client-kafka-shaded/pom.xml b/pulsar-client-kafka-compat/pulsar-client-kafka-shaded/pom.xml
index 8021fad..383203e 100644
--- a/pulsar-client-kafka-compat/pulsar-client-kafka-shaded/pom.xml
+++ b/pulsar-client-kafka-compat/pulsar-client-kafka-shaded/pom.xml
@@ -27,7 +27,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar-client-kafka-compat</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-client-kafka-compat/pulsar-client-kafka-shaded_0_8/pom.xml b/pulsar-client-kafka-compat/pulsar-client-kafka-shaded_0_8/pom.xml
index 6cf6c84..29b8e46 100644
--- a/pulsar-client-kafka-compat/pulsar-client-kafka-shaded_0_8/pom.xml
+++ b/pulsar-client-kafka-compat/pulsar-client-kafka-shaded_0_8/pom.xml
@@ -27,7 +27,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar-client-kafka-compat</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-client-kafka-compat/pulsar-client-kafka-shaded_0_9/pom.xml b/pulsar-client-kafka-compat/pulsar-client-kafka-shaded_0_9/pom.xml
index a6a7ba3..00bdb18 100644
--- a/pulsar-client-kafka-compat/pulsar-client-kafka-shaded_0_9/pom.xml
+++ b/pulsar-client-kafka-compat/pulsar-client-kafka-shaded_0_9/pom.xml
@@ -27,7 +27,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar-client-kafka-compat</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-client-kafka-compat/pulsar-client-kafka-tests/pom.xml b/pulsar-client-kafka-compat/pulsar-client-kafka-tests/pom.xml
index 5cb5582..6ccd8b8 100644
--- a/pulsar-client-kafka-compat/pulsar-client-kafka-tests/pom.xml
+++ b/pulsar-client-kafka-compat/pulsar-client-kafka-tests/pom.xml
@@ -27,7 +27,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar-client-kafka-compat</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-client-kafka-compat/pulsar-client-kafka-tests_0_8/pom.xml b/pulsar-client-kafka-compat/pulsar-client-kafka-tests_0_8/pom.xml
index 151ad4a..d9c6b3e 100644
--- a/pulsar-client-kafka-compat/pulsar-client-kafka-tests_0_8/pom.xml
+++ b/pulsar-client-kafka-compat/pulsar-client-kafka-tests_0_8/pom.xml
@@ -27,7 +27,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar-client-kafka-compat</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-client-kafka-compat/pulsar-client-kafka-tests_0_9/pom.xml b/pulsar-client-kafka-compat/pulsar-client-kafka-tests_0_9/pom.xml
index 1d82041..6ac87b8 100644
--- a/pulsar-client-kafka-compat/pulsar-client-kafka-tests_0_9/pom.xml
+++ b/pulsar-client-kafka-compat/pulsar-client-kafka-tests_0_9/pom.xml
@@ -27,7 +27,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar-client-kafka-compat</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-client-kafka-compat/pulsar-client-kafka/pom.xml b/pulsar-client-kafka-compat/pulsar-client-kafka/pom.xml
index 8f03825..27bfb8c 100644
--- a/pulsar-client-kafka-compat/pulsar-client-kafka/pom.xml
+++ b/pulsar-client-kafka-compat/pulsar-client-kafka/pom.xml
@@ -27,7 +27,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar-client-kafka-compat</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-client-kafka-compat/pulsar-client-kafka_0_8/pom.xml b/pulsar-client-kafka-compat/pulsar-client-kafka_0_8/pom.xml
index 2a297ef..b1e3105 100644
--- a/pulsar-client-kafka-compat/pulsar-client-kafka_0_8/pom.xml
+++ b/pulsar-client-kafka-compat/pulsar-client-kafka_0_8/pom.xml
@@ -27,7 +27,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar-client-kafka-compat</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-client-kafka-compat/pulsar-client-kafka_0_9/pom.xml b/pulsar-client-kafka-compat/pulsar-client-kafka_0_9/pom.xml
index 0740e78..b2466c7 100644
--- a/pulsar-client-kafka-compat/pulsar-client-kafka_0_9/pom.xml
+++ b/pulsar-client-kafka-compat/pulsar-client-kafka_0_9/pom.xml
@@ -27,7 +27,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar-client-kafka-compat</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-flink/pom.xml b/pulsar-flink/pom.xml
index f348efa..b44338f 100644
--- a/pulsar-flink/pom.xml
+++ b/pulsar-flink/pom.xml
@@ -26,7 +26,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-log4j2-appender/pom.xml b/pulsar-log4j2-appender/pom.xml
index bd3cee9..0866c1f 100644
--- a/pulsar-log4j2-appender/pom.xml
+++ b/pulsar-log4j2-appender/pom.xml
@@ -24,7 +24,7 @@
 	<parent>
 		<groupId>org.apache.pulsar</groupId>
 		<artifactId>pulsar</artifactId>
-		<version>2.5.0-SNAPSHOT</version>
+		<version>2.6.0-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 
diff --git a/pulsar-spark/pom.xml b/pulsar-spark/pom.xml
index 31dd50c..97b4d68 100644
--- a/pulsar-spark/pom.xml
+++ b/pulsar-spark/pom.xml
@@ -26,7 +26,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/pulsar-storm/pom.xml b/pulsar-storm/pom.xml
index d5049ea..aa72385 100644
--- a/pulsar-storm/pom.xml
+++ b/pulsar-storm/pom.xml
@@ -26,7 +26,7 @@
   <parent>
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar</artifactId>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
     <relativePath>..</relativePath>
   </parent>