Add option to disable automatic jMolecules ArchUnit rule verification

[xenoterracide]

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Due to what appears to be a bug in archunit I'm looking at possibly writing this integration testing manually but the documentation doesn't seem to imply that I can disable this if I provide archunit.

Spring Modulith optionally integrates with the jMolecules ArchUnit library and, if present, automatically triggers its Domain-Driven Design verification rules described here.

not certain if this is a missing feature or simply a need to document.