[Release] 4.4.0

[felipeelia]

• 1. If the new version requires a reindex, add its number to the $reindex_versions array in the ElasticPress\Upgrades::check_reindex_needed() method. If it is the case, remember to add that information to the Changelog listings in readme.txt and CHANGELOG.md.
• 2. Branch: Starting from develop, cut a release branch named release/4.4.0 for your changes.
• 3. Version bump: Bump the version number in elasticpress.php, package.json, package-lock.json, readme.txt, and any other relevant files if it does not already reflect the version being released. In elasticpress.php update both the plugin "Version:" property and the plugin EP_VERSION constant.
• 4. Changelog: Add/update the changelog in CHANGELOG.md and readme.txt, ensuring to link the [4.4.0] release reference in the footer of CHANGELOG.md (e.g., https://github.com/10up/ElasticPress/compare/4.3.1..4.4.0).
• 5. Props: Update CREDITS.md file with any new contributors, confirm maintainers are accurate.
• 6. Readme updates: Make any other readme changes as necessary. README.md is geared toward GitHub and readme.txt contains WordPress.org-specific content. The two are slightly different.
• 7. New files: Check to be sure any new files/paths that are unnecessary in the production version are included in .distignore.
• 8. POT file: Run wp i18n make-pot . lang/elasticpress.pot and commit the file.
• 9. Release date: Double check the release date in both changelog files.
• 10. Merge: Merge the release branch/PR into develop, then make a non-fast-forward merge from develop into trunk (git checkout trunk && git merge --no-ff develop). trunk contains the stable development version.
• 11. Test: While still on the trunk branch, test for functionality locally.
• 12. Push: Push your trunk branch to GitHub (e.g. git push origin trunk).
• 13. Check the Build and Tag action: a new tag named with the version number should've been created. It should contain all the built assets.
• 14. Release: Create a new release, naming the release with the new version number, and targeting the tag created in the previous step. Paste the release changelog from CHANGELOG.md into the body of the release and include a link to the closed issues on the milestone.
• 15. SVN: Wait for the GitHub Action to finish deploying to the WordPress.org repository. If all goes well, users with SVN commit access for that plugin will receive an emailed diff of changes.
• 16. Check WordPress.org: Ensure that the changes are live on https://wordpress.org/plugins/elasticpress/. This may take a few minutes.
• 17. 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.
• 18. Punt incomplete items: If any open issues or PRs which were milestoned for 4.4.0 do not make it into the release, update their milestone to 4.4.1, 4.5.0, 5.0.0 or Future Release.