HBASE-28022 Remove netty 3 dependency in the pom file for hbase-endpoint (#5351)

Signed-off-by: Xin Sun <ddupgs@gmail.com>
Signed-off-by: GeorryHuang <huangzhuoyue@apache.org>
(cherry picked from commit 5464245)

Author: Apache9

hbase-endpoint/pom.xml

@@ -386,13 +386,6 @@
             </exclusion>
           </exclusions>
         </dependency>
-        <!-- Hadoop needs Netty 3.x at test scope for the minicluster -->
-        <dependency>
-          <groupId>io.netty</groupId>
-          <artifactId>netty</artifactId>
-          <version>3.6.2.Final</version>
-          <scope>test</scope>
-        </dependency>
         <dependency>
           <groupId>org.apache.hadoop</groupId>
           <artifactId>hadoop-minikdc</artifactId>