Update docker.io/library/postgres Docker tag to v18

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

@@ -46,7 +46,7 @@ services:
       - "8080:8080"
 
   db:
-    image: docker.io/library/postgres:15.14
+    image: docker.io/library/postgres:18.0@sha256:9a2e0383c38afd52cff14eeefe2b806fcde406b317002cd13ce513d309942751
     restart: unless-stopped
     networks:
       - keycloak

resources/chaosknoten/lists/docker_compose/compose.yaml

@@ -56,7 +56,7 @@ services:
       - POSTGRES_DB=mailmandb
       - POSTGRES_USER=mailman
       - POSTGRES_PASSWORD=wvQjbMRnwFuxGEPz
-    image: docker.io/library/postgres:12-alpine
+    image: docker.io/library/postgres:18-alpine@sha256:f898ac406e1a9e05115cc2efcb3c3abb3a92a4c0263f3b6f6aaae354cbb1953a
     volumes:
       - /opt/mailman/database:/var/lib/postgresql/data
     networks:

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

@@ -3,7 +3,7 @@
 
 services:
   database:
-    image: docker.io/library/postgres:15-alpine
+    image: docker.io/library/postgres:18-alpine@sha256:f898ac406e1a9e05115cc2efcb3c3abb3a92a4c0263f3b6f6aaae354cbb1953a
     environment:
       - "POSTGRES_USER=hedgedoc"
       - "POSTGRES_PASSWORD={{ secret__hedgedoc_db_password }}"

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

@@ -3,7 +3,7 @@
 
 services:
   database:
-    image: docker.io/library/postgres:15-alpine
+    image: docker.io/library/postgres:18-alpine@sha256:f898ac406e1a9e05115cc2efcb3c3abb3a92a4c0263f3b6f6aaae354cbb1953a
     environment:
       - "POSTGRES_USER=pretalx"
       - "POSTGRES_PASSWORD={{ secret__pretalx_db_password }}"

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

@@ -1,7 +1,7 @@
 ---
 services:
   database:
-    image: docker.io/library/postgres:15-alpine
+    image: docker.io/library/postgres:18-alpine@sha256:f898ac406e1a9e05115cc2efcb3c3abb3a92a4c0263f3b6f6aaae354cbb1953a
     environment:
       - "POSTGRES_USER=pretix"
       - "POSTGRES_PASSWORD={{ secret__pretix_db_password }}"