chore(deps): bump cryptography from 48.0.1 to 50.0.0 in /backend

Bumps [cryptography](https://github.com/pyca/cryptography) from 48.0.1 to 50.0.0.
- [Changelog](https://github.com/pyca/cryptography/blob/main/CHANGELOG.rst)
- [Commits](pyca/cryptography@48.0.1...50.0.0)

---
updated-dependencies:
- dependency-name: cryptography
  dependency-version: 50.0.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

backend/requirements.txt

@@ -16,7 +16,7 @@ charset-normalizer==3.0.1
 click==8.1.7
 constantly==15.1.0
 crontab==1.0.1
-cryptography==48.0.1
+cryptography==50.0.0
 defusedxml==0.7.1
 dj-rest-auth==7.0.1
 Django==4.2.30