Add build tooling to support releasing patches, i.e. 1.3.2.1

[jack-berg]

Build tooling to release patches when there is no corresponding release from opentelemetry-proto.

For example, to release a patch for 1.3.2:

• run the release build action
• Set the release version argument to 1.3.2.1
• This will publish a release with version 1.3.2.1, but which uses opentelemetry-proto sources from the 1.3.2 release tag

See #17 for more info.

[breedx-splk]

Still feels weird, but also seems like a nice compromise given the challenges in keeping the versions somewhat sync'd.

[trask]

with the caveat that I don't fully understand (or like) nebular 🪄 versioning 😄

[jack-berg]

The release was successfully staged to sonatype, but failed to finish publishing: https://github.com/open-telemetry/opentelemetry-proto-java/actions/runs/11111731756/job/30872304418

• What went wrong:
  Execution failed for task ':release'.
  version should not be set in build file when using nebula-release plugin. Instead use -Prelease.version parameter

So weird for the nebula plugin to partially succeed, only to have a later task reject the way that release.version is specified.

[jack-berg]

Also weird that two artifacts ended up in sonatype: 1.3.2 and 1.3.2.1.

🤔

Obviously I should go and fix this, but I'm also tempted to close (i.e. release) the staged 1.3.2.1 artifact.