precommit should not run all java goals when given a docs-only patch

Right now docs-only patches (those that only impact the top level src/main/site, src/main/asciidoc, or src/main/xslt) run through all of the java related precommit checks, including test4tests and the full unit test suite.

Since we know these paths don't require those checks, we should update our personality to skip them. (or fix our project structure to match "the maven way".)