Apache Beam 2.14.0 Release

Merge pull request apache#9148 from akedin/revert-move-to-215-on-214-…

…branch

Revert moving to 2.15.0-SNAPSHOT on 2.14.0 branch

Tagging 2.13.0 release to 2.13.0 RC2

[Gradle Release Plugin] - creating tag: 'v2.13.0-RC2'.

[Gradle Release Plugin] - pre tag commit: 'v2.13.0-RC1'.

The Java Unified Local Runner (a.k.a Reference Runner) is removed by …

…this commit.

Beam 2.12.0

[Gradle Release Plugin] - creating tag: 'v2.12.0-RC4'.

[Gradle Release Plugin] - creating tag: 'v2.12.0-RC3'.

[Gradle Release Plugin] - creating tag: 'v2.12.0-RC2'.