Cleanup pom files in the tests module (#6421)

### Modifications

- Removed dependencies on test libraries that were already imported in the parent pom file.

- Removed groupId tags that are inherited from the parent pom file.

diff --git a/tests/bc_2_0_0/pom.xml b/tests/bc_2_0_0/pom.xml
index 2619d44..f691174 100644
--- a/tests/bc_2_0_0/pom.xml
+++ b/tests/bc_2_0_0/pom.xml
@@ -35,12 +35,6 @@
     <dependencies>
 
         <dependency>
-            <groupId>org.testng</groupId>
-            <artifactId>testng</artifactId>
-            <scope>test</scope>
-        </dependency>
-
-        <dependency>
             <groupId>com.google.code.gson</groupId>
             <artifactId>gson</artifactId>
             <scope>test</scope>
diff --git a/tests/bc_2_0_1/pom.xml b/tests/bc_2_0_1/pom.xml
index 67e7621..205b746 100644
--- a/tests/bc_2_0_1/pom.xml
+++ b/tests/bc_2_0_1/pom.xml
@@ -35,12 +35,6 @@
     <dependencies>
 
         <dependency>
-            <groupId>org.testng</groupId>
-            <artifactId>testng</artifactId>
-            <scope>test</scope>
-        </dependency>
-
-        <dependency>
             <groupId>com.google.code.gson</groupId>
             <artifactId>gson</artifactId>
             <scope>test</scope>
diff --git a/tests/docker-images/java-test-functions/pom.xml b/tests/docker-images/java-test-functions/pom.xml
index aad909b..c801c00 100644
--- a/tests/docker-images/java-test-functions/pom.xml
+++ b/tests/docker-images/java-test-functions/pom.xml
@@ -26,7 +26,6 @@
         <version>2.6.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
-    <groupId>org.apache.pulsar.tests</groupId>
     <artifactId>java-test-functions</artifactId>
     <name>Apache Pulsar :: Tests :: Docker Images :: Java Test Functions</name>
     <dependencies>
diff --git a/tests/docker-images/latest-version-image/pom.xml b/tests/docker-images/latest-version-image/pom.xml
index 5a961b0..fabbbc7 100644
--- a/tests/docker-images/latest-version-image/pom.xml
+++ b/tests/docker-images/latest-version-image/pom.xml
@@ -26,7 +26,6 @@
     <version>2.6.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
-  <groupId>org.apache.pulsar.tests</groupId>
   <artifactId>latest-version-image</artifactId>
   <name>Apache Pulsar :: Tests :: Docker Images :: Latest Version Testing</name>
   <packaging>pom</packaging>
diff --git a/tests/docker-images/pom.xml b/tests/docker-images/pom.xml
index ca052a2..8241abf 100644
--- a/tests/docker-images/pom.xml
+++ b/tests/docker-images/pom.xml
@@ -28,7 +28,6 @@
     <artifactId>tests-parent</artifactId>
     <version>2.6.0-SNAPSHOT</version>
   </parent>
-  <groupId>org.apache.pulsar.tests</groupId>
   <artifactId>docker-images</artifactId>
   <name>Apache Pulsar :: Tests :: Docker Images</name>
   <modules>
diff --git a/tests/integration/pom.xml b/tests/integration/pom.xml
index 6f24ed5..4a3016e 100644
--- a/tests/integration/pom.xml
+++ b/tests/integration/pom.xml
@@ -38,11 +38,6 @@
 
   <dependencies>
     <dependency>
-      <groupId>org.testng</groupId>
-      <artifactId>testng</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
       <groupId>com.google.code.gson</groupId>
       <artifactId>gson</artifactId>
       <scope>test</scope>
diff --git a/tests/pulsar-spark-test/pom.xml b/tests/pulsar-spark-test/pom.xml
index 3d286cb..3d9856f 100644
--- a/tests/pulsar-spark-test/pom.xml
+++ b/tests/pulsar-spark-test/pom.xml
@@ -57,12 +57,6 @@
         </dependency>
 
         <dependency>
-          <groupId>org.mockito</groupId>
-          <artifactId>mockito-core</artifactId>
-          <scope>test</scope>
-        </dependency>
-
-        <dependency>
           <groupId>org.apache.spark</groupId>
           <artifactId>spark-streaming_2.10</artifactId>
           <scope>test</scope>