[MCLEAN-127] Use Files.createSymbolicLink instead of shelling out - #65

Caused by: org.apache.maven.plugin.PluginIncompatibleException: The plugin org.apache.maven.plugins:maven-clean-plugin:4.0.0-beta-2-SNAPSHOT has unmet prerequisites: Required Maven version 4.0.0-beta-5 is not met by current version 4.0.0-beta-3

No, but:

[INFO] Build Summary:
[INFO]   Passed: 9, Failed: 2, Errors: 0, Skipped: 0
[INFO] -------------------------------------------------
Error:  The following builds failed:
Error:  *  symlink-dont-follow/pom.xml
Error:  *  dangling-symlinks/pom.xml

GH Actions should be observed, the Jenkins instance is not setup (yet?)
If you want to change maven3 plugin, use the branch https://github.com/apache/maven-clean-plugin/tree/maven-clean-plugin-3.x

Yes, those two failing tests are weird. It looks like Beanshell is having trouble matching the argument types and is looking for a method that matches the actual type rather than the interface supertype.

Failures now appear to be in the CI script:

plugin:4.0.0-beta-2-SNAPSHOT:clean (default-clean) on project exclude-default-dirs: The plugin org.apache.maven.plugins:maven-clean-plugin:4.0.0-beta-2-SNAPSHOT has unmet prerequisites: Required Maven version 4.0.0-beta-5 is not met by current version 4.0.0-beta-3

Resolve #148