deps(docker): bump bitnami/postgresql in /docker/postgresql (#2695)

Bumps bitnami/postgresql from 15 to 16.

---
updated-dependencies:
- dependency-name: bitnami/postgresql
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

docker/postgresql/Dockerfile

@@ -1,4 +1,4 @@
-FROM bitnami/postgresql:15
+FROM bitnami/postgresql:16
 
 USER root