Bump psycopg2 from 2.9.3 to 2.9.4

Bumps [psycopg2](https://github.com/psycopg/psycopg2) from 2.9.3 to 2.9.4.
- [Release notes](https://github.com/psycopg/psycopg2/releases)
- [Changelog](https://github.com/psycopg/psycopg2/blob/master/NEWS)
- [Commits](https://github.com/psycopg/psycopg2/commits)

---
updated-dependencies:
- dependency-name: psycopg2
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

requirements/production.txt

@@ -15,7 +15,7 @@ gunicorn==20.1.0
 pinax-eventlog==5.1.1
 pip==22.3
 -e git+https://github.com/pretalx/pretalx@11652a5857316b2280b16305621a0088d19adf12#egg=pretalx[redis]&subdirectory=src
-psycopg2==2.9.3
+psycopg2==2.9.4
 pytz==2022.5
 sentry-sdk==1.10.0
 virtualenv==20.16.5