Fix part of main build by using release configuration for maven-compiler-plugin

[apupier]

main branch currently failing with:

Error:  Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.11.0:compile (default-compile) on project camel-example-aggregate-dist: Compilation failure
Error:  /home/runner/work/camel-examples/camel-examples/aggregate-dist/src/main/java/org/apache/camel/example/Application.java:[72,36] method references are not supported in -source 7
Error:    (use -source 8 or higher to enable method references)

[apupier]

it will remain a lot of build errors due to setUp and tearDown methods set as final and also Kotlin not compiling (for incompatibility binary compilation)