Release version 2.5.1

[dkotter]

This issue is for tracking changes for the 2.5.1 release. Target release date: January 2024.

Pre-release steps

• Final review/merge of Switch from the deprecated Completions API to the Models API #654

Release steps

• Branch: Starting from develop, cut a release branch named release/2.5.1 for your changes.
• Version bump: Bump the version number in classifai.php, config.php, package-lock.json, package.json, and readme.txt if it does not already reflect the version being released.
• Changelog: Add/update the changelog in CHANGELOG.md.
• Props: Update CREDITS.md file with any new contributors, confirm maintainers are accurate.
• Readme updates: Make any other readme changes as necessary in README.md and readme.txt.
• New files: Check to be sure any new files/paths that are unnecessary in the production version are included in .gitattributes.
• Merge: Make a non-fast-forward merge from your release branch to develop (or merge the pull request), then do the same for develop into trunk, ensuring you pull the most recent changes into develop first (git checkout develop && git pull origin develop && git checkout trunk && git merge --no-ff develop). trunk contains the stable development version.
• Push: Push your trunk branch to GitHub (e.g. git push origin trunk).
• Compare trunk to develop to ensure no additional changes were missed.
• Wait for build: Head to the Actions tab in the repo and wait for it to finish if it hasn't already. If it doesn't succeed, figure out why and start over.
• Check the build: Check out the stable branch and test for functionality locally
• Release: Create a new release, naming the tag and the release with the new version number, and targeting the stable branch. Paste the changelog from CHANGELOG.md into the body of the release and include a link to the closed issues on the milestone (e.g. https://github.com/10up/classifai/milestone/31?closed=1).
• Close milestone: Edit the milestone with release date (in the Due date (optional) field) and link to GitHub release (in the Description field), then close the milestone.
• Punt incomplete items: If any open issues or PRs which were milestoned for 2.5.1 do not make it into the release, update their milestone to 2.6.0 or Future Release.
• Version bump (again): In the develop branch (cd ../ && git checkout develop) bump the version number in classifai.php to 2.6.0-dev. It's okay if the next release might be a different version number; that change can be handled right before release in the first step, as might also be the case with @since annotations.