Building Java should be disabled by default

[simonjwright]

Building v24.0.0, I have to do

    python manage.py                            \
           build                                \
           --disable-java

or I get

Building the Java bindings...
Maven-Command failed: error while running mvn -f /Volumes/Miscellaneous3/src/libadalang/build/java/pom.xml clean package -q:
    [Errno 2] No such file or directory: 'mvn'

I don't have mvn installed, because I didn't know I might need to.

I think that people who want Java support should have to say --enable-java.

[raph-amiard]

Hi @simonjwright! Thanks for the feedback.

This is a consequence of our internal build chain: Most of LAL developpers in-house will need the Java bindings anyway. We'll discuss to see if there's something more user friendly to do for external contributors.

Kind regards

[simonjwright]

OK. But, would it be possible to alter user_manual/building.rst to mention this? (I could raise a PR if that would help? at least it would be from the viewpoint of an external user!)