Bump version to 2.6.0 (#5820)

*Motivation*

Bump the development version to 2.6.0-SNAPSHOT
diff --git a/pulsar-sql/pom.xml b/pulsar-sql/pom.xml
index 743e661..fd595bb 100644
--- a/pulsar-sql/pom.xml
+++ b/pulsar-sql/pom.xml
@@ -25,7 +25,7 @@
     <parent>
         <groupId>org.apache.pulsar</groupId>
         <artifactId>pulsar</artifactId>
-        <version>2.5.0-SNAPSHOT</version>
+        <version>2.6.0-SNAPSHOT</version>
     </parent>
 
     <artifactId>pulsar-sql</artifactId>
diff --git a/pulsar-sql/presto-distribution/pom.xml b/pulsar-sql/presto-distribution/pom.xml
index e918ca5..dbe2ba4 100644
--- a/pulsar-sql/presto-distribution/pom.xml
+++ b/pulsar-sql/presto-distribution/pom.xml
@@ -31,7 +31,7 @@
     <groupId>org.apache.pulsar</groupId>
     <artifactId>pulsar-presto-distribution</artifactId>
     <name>Pulsar SQL :: Pulsar Presto Distribution</name>
-    <version>2.5.0-SNAPSHOT</version>
+    <version>2.6.0-SNAPSHOT</version>
 
     <properties>
         <presto.version>0.206</presto.version>
diff --git a/pulsar-sql/presto-pulsar-plugin/pom.xml b/pulsar-sql/presto-pulsar-plugin/pom.xml
index 9a5754b..d90b20b 100644
--- a/pulsar-sql/presto-pulsar-plugin/pom.xml
+++ b/pulsar-sql/presto-pulsar-plugin/pom.xml
@@ -25,7 +25,7 @@
     <parent>
         <groupId>org.apache.pulsar</groupId>
         <artifactId>pulsar-sql</artifactId>
-        <version>2.5.0-SNAPSHOT</version>
+        <version>2.6.0-SNAPSHOT</version>
     </parent>
 
     <artifactId>pulsar-presto-connector</artifactId>
diff --git a/pulsar-sql/presto-pulsar/pom.xml b/pulsar-sql/presto-pulsar/pom.xml
index 2f3d4fd..87dfa28 100644
--- a/pulsar-sql/presto-pulsar/pom.xml
+++ b/pulsar-sql/presto-pulsar/pom.xml
@@ -25,7 +25,7 @@
     <parent>
         <groupId>org.apache.pulsar</groupId>
         <artifactId>pulsar-sql</artifactId>
-        <version>2.5.0-SNAPSHOT</version>
+        <version>2.6.0-SNAPSHOT</version>
     </parent>
 
     <artifactId>pulsar-presto-connector-original</artifactId>