[bug#48766] [PATCH] gnu: java-jmh: Switch to maven-build-system.

[Julien Lepiller]

Hi Guix!

I'm excited to submit this patch series, as it adds the first package
to guix that uses the maven-build-system.

The series first improves the maven build system, so it actually works
with jmh :)

The series then changes a few dependencies to install to the maven
repository structure (lib/m2), so they can be detected by maven during
the build.

Since the series updates files that are used by the ant-build-system,
it unfortunately needs to update all java packages. Grepping for
"build-system ant-build-system", it shows 302 packages, which is
two packages above the limit for master. However, since most java
packages are fast to build, I'd like to ask for an exception to this
rule and push to master directly.

Patches will follow :)