Require Java 11 in stream Java client projects

References rabbitmq/rabbitmq-stream-java-client#663

(cherry picked from commit c17d38e)
(cherry picked from commit 675586e)

Author: acogoluegnes

Diff for: deps/rabbitmq_stream/test/rabbit_stream_SUITE_data/pom.xml

@@ -83,8 +83,7 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>${maven.compiler.plugin.version}</version>
                 <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
+                    <release>11</release>
                     <compilerArgs>
                         <arg>-Xlint:deprecation</arg>
                         <arg>-Xlint:unchecked</arg>

Diff for: deps/rabbitmq_stream_management/test/http_SUITE_data/pom.xml

@@ -99,8 +99,7 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>${maven.compiler.plugin.version}</version>
                 <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
+                    <release>11</release>
                     <compilerArgs>
                         <arg>-Xlint:deprecation</arg>
                         <arg>-Xlint:unchecked</arg>