Bump pem from 21.2.0 to 23.1.0 (from PR #3581)

Bumps [pem](https://github.com/sponsors/hynek) from 21.2.0 to 23.1.0.
- [Commits](https://github.com/sponsors/hynek/commits)

requirements.txt

@@ -22,7 +22,7 @@ google-measurement-protocol==1.1.0
 gunicorn==20.1.0
 jwcrypto==1.5.0
 markus[datadog]==4.2.0
-pem==21.2.0
+pem==23.1.0
 psycopg2==2.9.6
 PyJWT==2.7.0
 python-decouple==3.8