Don't restore the Maven cache in the release workflow #110

Every job in build-all-and-publish.yml restores setup-java cache: maven (lines 74, 132, 177, 232, 245). That includes the native build jobs and the credentialed publish step. docs.yml (line 27) and test.yml run on the same refs and share the same key (setup-java-<os>-maven-<hash(pom.xml)>).

pom.xml has a fixed version, so the key rarely changes, and any job on the same ref or on main can write to it. That includes code running inside the docs job (unpinned PyPI dependencies), whether or not cache: maven is set there. A poisoned ~/.m2 would then flow into the native libraries and the signed jar.

Fix: remove cache: maven from every setup-java step in build-all-and-publish.yml. Removing it from docs.yml alone is not enough, because only the reading side can be fixed. Releases are rare, so downloading fresh from Central costs a few minutes at most. test.yml can keep its cache.