Upgrade ansible-role-postgres (v18.4-0 -> v18.4-1)

Pulls in the pgloader connection string handling fix, which keeps the
Postgres password out of the command line and Ansible error output.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

requirements.yml

@@ -57,7 +57,7 @@
   version: dd6e15246b7a9a2d921e0b3f9cd8a4a917a1bb2f
   name: playbook_state_preserver
 - src: git+https://github.com/mother-of-all-self-hosting/ansible-role-postgres.git
-  version: v18.4-0
+  version: v18.4-1
   name: postgres
 - src: git+https://github.com/mother-of-all-self-hosting/ansible-role-postgres-backup.git
   version: v18-3