jars don't match official docs for 3.0

Over at LibreOffice, we noticed that java-hamcrest 3.0 still ships as split jars: https://gitlab.archlinux.org/archlinux/packaging/packages/java-hamcrest/-/blob/0dadba26df3b5351de1d8838b7bdb5af644e4d70/PKGBUILD

https://hamcrest.org/JavaHamcrest/distributables#the-hamcrest-jar

https://hamcrest.org/JavaHamcrest/distributables#previous-versions-of-hamcrest

Comment from our release engineer:

"Switch to single hamcrest.jar was already done for hamcrest 2 (and 2.1, added the core and library ones as shims/stubs kept as transitional helpers) - and looking at hamcrest.org overriding the generator jar is an actual bug, the integration.jar and generator.jar still are separate/the same since 1.3 - so arch packages wanting to use the generator one are now broken/using generator.jar as hamcrest in configure most definitely is a no-go"