Play Framework

fix: stop ant package from leaking gradle caches into the dist

The artifact target's fileset excluded `.github` as a bare entry — that
matches a literal file by that name, not the directory tree — so all
of `.github/` (workflows, ISSUE_TEMPLATE, ~20 KB) was getting packaged.
More importantly, `.gradle/` (~1.4 MB), `.kotlin/`, top-level `build/`
(~2.9 MB), and `framework/gradle-plugin/build/` weren't excluded at all.
None of those existed when this exclude list was last touched — they
arrived with the PF-90 Gradle migration.

Fix `.github` → `.github/**`, and add `**/.gradle/**`, `**/.kotlin/**`,
`build/**`, and `framework/gradle-plugin/build/**`. The `**/.foo/**`
shape mirrors the existing `**/.git/**` and `**/.bzr/**` entries so
nested gradle/kotlin caches under any subproject are also caught.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>