chore(deps): bump black from 24.1a1 to 24.3.0 in /backend

Bumps [black](https://github.com/psf/black) from 24.1a1 to 24.3.0.
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](https://github.com/psf/black/commits/24.3.0)

---
updated-dependencies:
- dependency-name: black
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

backend/requirements.txt

@@ -10,7 +10,7 @@ bcrypt==4.1.2
 beautifulsoup4==4.12.3
 bidict==0.23.1
 billiard==4.2.0
-black==24.1a1
+black==24.3.0
 blinker==1.7.0
 blurhash-python==1.2.2
 celery==5.3.6