Release instructions

Preparing a new major or minor release

Run the Prepare release branch workflow.
- Press the "Run workflow" button, and leave the default branch main selected.
  - If making a pre-release of stable components (e.g. release candidate), enter the pre-release version number, e.g. 1.9.0rc2. (otherwise the workflow will pick up the version from main and just remove the .dev suffix).
- Review and merge the two pull requests that it creates (one is targeted to the release branch and one is targeted to main).

Backport pull request(s) to the release branch.
- Run the Backport workflow.
- Press the "Run workflow" button, then select the release branch from the dropdown list, e.g. release/v1.9.x, then enter the pull request number that you want to backport, then click the "Run workflow" button below that.
- Review and merge the backport pull request that it generates.
Merge a pull request to the release branch updating the CHANGELOG.md.
- The heading for the unreleased entries should be ## Unreleased.
Run the Prepare patch release workflow.
- Press the "Run workflow" button, then select the release branch from the dropdown list, e.g. release/v1.9.x, and click the "Run workflow" button below that.
- Review and merge the pull request that it creates for updating the version.

Run the Release workflow.
- Press the "Run workflow" button, then select the release branch from the dropdown list, e.g. release/v1.9.x, and click the "Run workflow" button below that.
- This workflow will publish the artifacts and publish a GitHub release with release notes based on the change log.
- Review and merge the pull request that it creates for updating the change log in main (note that if this is not a patch release then the change log on main may already be up-to-date, in which case no pull request will be created).

The version number for stable components in the main branch is always X.Y.0.dev, where X.Y.0 represents the next minor release.
When the release branch is created, you can opt to make a "pre-release", e.g. X.Y.0rc2.
If you ARE NOT making a "pre-release":
- A "long-term" release branch will be created, e.g. release/v1.9.x-0.21bx (notice the wildcard x's). Later on, after the initial release, you can backport PRs to a "long-term" release branch and make patch releases from it.
- The version number for stable components in the release branch will be bumped to remove the .dev, e.g. X.Y.0.
- The version number for stable components in the main branch will be bumped to the next version, e.g. X.{Y+1}.0.dev.
If you ARE making a "pre-release":
- A "short-term" release branch will be created, e.g. release/v1.9.0rc2-0.21b0 (notice the precise version with no wildcard x's). "Short-term" release branches do not support backports or patch releases after the initial release.
- The version number for stable components in the main branch will not be bumped, e.g. it will remain X.Y.0.dev since the next minor release will still be X.Y.0.

The version number for unstable components in the main branch is always 0.Yb0.dev, where 0.Yb0 represents the next minor release.
- Question: Is "b" (beta) redundant on "0." releases, or is this a python thing? I'm wondering if we can change it to 0.Y.0 to match up with the practice in js and go repos.
Unstable components do not need "pre-releases", and so whether or not you are making a "pre-release" of stable components:
- The version number for unstable components in the release branch will be bumped to remove the .dev, e.g. 0.Yb0.
- The version number for unstable components in the main branch will be bumped to the next version, e.g. 0.{Y+1}b0.dev.

Check PyPI
- This should be handled automatically on release by the publish action.
- Check the action logs to make sure packages have been uploaded to PyPI
- Check the release history (e.g. https://pypi.org/project/opentelemetry-api/#history) on PyPI
- If for some reason the action failed, see Publish failed below
Move stable tag
- Run the following (TODO automate):
```
git tag -d stable
git tag stable
git push --delete origin tagname
git push origin stable
```
- This will ensure the docs are pointing at the stable release.
- To validate this worked, ensure the stable build has run successfully: https://readthedocs.org/projects/opentelemetry-python/builds/. If the build has not run automatically, it can be manually trigger via the readthedocs interface.

If for some reason the action failed, do it manually:

Switch to the release branch (important so we don't publish packages with "dev" versions)
Build distributions with ./scripts/build.sh
Delete distributions we don't want to push (e.g. testutil)
Push to PyPI as twine upload --skip-existing --verbose dist/*
Double check PyPI!