Follow up to release automation

- [ ] automatically set date to release description in GitHub releases. [Related discussion in PR](https://github.com/JanusGraph/janusgraph/pull/2941#discussion_r785506209)
- [ ] Publish snapshot releases for all commits. [Releated discussion in PR](https://github.com/JanusGraph/janusgraph/pull/2941#discussion_r785508294), [Related discussion in mailing lists](https://lists.lfaidata.foundation/g/janusgraph-dev/topic/discussion_release_snapshot/84922650?p=,,,20,0,0,0::recentpostdate/sticky,,,20,2,0,84922650,previd=1642179578049843803,nextid=1613096947766667047&previd=1642179578049843803&nextid=1613096947766667047)
- [ ] Publish java-11 builds alongside java-8 builds. [Related discussion in PR](https://github.com/JanusGraph/janusgraph/pull/2941#discussion_r785508761)

Start with the related discussions in PR #2941 and the linked mailing-list discussion to understand the release automation context. Done means automatically setting release-description dates, publishing snapshots for every commit, and producing Java 11 builds alongside Java 8 builds.

Written by the indexing model from the issue text.