Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

Set Content-Length to 0 and close output stream after writing.

So that mvn appengine:stop works again (same in Gradle)

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

* build(deps): remove untrusted plugin dependencies for Airlock

Upgrade and configure Maven build plugins so that all build and release dependencies resolve from Airlock maven-3p-trusted.

- Override org.codehaus.plexus:plexus-i18n to 1.0-beta-10 and exclude 1.0-beta-7 from maven-bundle-plugin and maven-plugin-plugin, because 1.0-beta-7 lacks machine-readable upstream license metadata.
- Upgrade maven-enforcer-plugin to 3.0.0, jacoco-maven-plugin to 0.8.12, maven-checkstyle-plugin to 3.6.0, and maven-javadoc-plugin to 3.11.2 to drop classworlds:classworlds:1.1-alpha-2.
- Upgrade maven-pmd-plugin to 3.21.2 and exclude org.codehaus.plexus:plexus-container-default so the verify phase uses trusted pmd-java:6.55.0 instead of 6.42.0.
- Pin maven-compiler-plugin, maven-javadoc-plugin, and maven-source-plugin in the jdk8 and root release profiles to avoid unpinned LATEST metadata lookups.

* build(deps): keep Doxia 1.11.1 for plugin:report and document enforcer pin

- Exclude doxia-core and doxia-sink-api from maven-reporting-impl:3.0.0 so maven-plugin-plugin:3.6.4 keeps Doxia 1.11.1 when running mvn plugin:report.
- Document why maven-enforcer-plugin stays below 3.2.0 while linkage-checker-enforcer-rules:0.2.0 uses AbstractNonCacheableEnforcerRule.