- Improved `craft\helpers\FileHelper::getExtensionByMimeType()` for some ambiguous, web-friendly MIME types.
- Removed the OAuth 2.0 Client library, as it’s no longer used in core.
- Fixed a bug where activation emails sent to newly-created users could link to the front-end site, if they were granted control panel access via a user group. ([#13204](https://github.com/craftcms/cms/issues/13204))