Release 3.9.2

[schlessera]

Release Changelog

• Fix: Check authorization on 'save_new_alert' AJAX action #1391, props marcS0H (WPScan)
• Development: Mark as tested with the latest version 6.1 of WordPress.
• Development: Update development dependencies.

Release Checklist

• [x] This pull request is to the master branch.
• [x] Release version follows semantic versioning. Does it include breaking changes?
• [x] Update changelog in readme.txt.
• [x] Bump version in stream.php.
• [x] Bump Stable tag in readme.txt.
• [x] Bump version in classes/class-plugin.php.
• [ ] Draft a release on GitHub.

Change [ ] to [x] to mark the items as done.

[schlessera]

@kasparsd I had to resolve a merge conflict, as the release 3.9.1 on master had not been immediately merged back into develop before subsequent PRs were merged into develop.

Can you please double-check the current commit chain works for you? Or let me know if you want me to further disentangle before a new release.

[schlessera]

For reference: I bumped the WP tested version to 6.1 after doing some basic testing with WordPress 6.1.1.