Bump pip from 22.3 to 22.3.1

Bumps [pip](https://github.com/pypa/pip) from 22.3 to 22.3.1.
- [Release notes](https://github.com/pypa/pip/releases)
- [Changelog](https://github.com/pypa/pip/blob/main/NEWS.rst)
- [Commits](pypa/pip@22.3...22.3.1)

---
updated-dependencies:
- dependency-name: pip
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

requirements/production.txt

@@ -12,7 +12,7 @@ django-timezone-field==4.2.3
 easy-thumbnails==2.8.3
 gunicorn==20.1.0
 pinax-eventlog==5.1.1
-pip==22.3
+pip==22.3.1
 -e git+https://github.com/pretalx/pretalx@9b0934c0cef6ec022608ff19ab15176528dac345#egg=pretalx[redis]&subdirectory=src
 psycopg2==2.9.4
 pytz==2022.5