Update docker.io/library/postgres Docker tag to v15

docs/concepts-and-configurations/matrix-moderation.md

@@ -5,7 +5,7 @@ title: Matrix Moderation
 # Matrix Moderation
 
 All Matrix rooms created around CCCHH and which are considered *official* are subject to centralized moderation.
-This moderation is enforced by a [Mjolnir](https://github.com/matrix-org/mjolnir) bot on a techincal level and operated by a dedicated sub-team of the Infra Group.
+This moderation is enforced by a [Draupnir](https://github.com/the-draupnir-project/Draupnir) bot on a techincal level and operated by a dedicated sub-team of the Infra Group.
 
 The moderation team can be reached at [matrix-moderation@hamburg.ccc.de](mailto:matrix-moderation@hamburg.ccc.de).
 

resources/chaosknoten/lists/docker_compose/compose.yaml.j2

@@ -62,7 +62,7 @@ services:
       - POSTGRES_DB=mailmandb
       - POSTGRES_USER=mailman
       - "POSTGRES_PASSWORD={{ secret__lists__postgres_password }}"
-    image: docker.io/library/postgres:12-alpine
+    image: docker.io/library/postgres:15-alpine
     volumes:
       - /opt/mailman/database:/var/lib/postgresql/data
     networks: