Update postgres Docker tag to v15

webserver/docker_keycloak/templates/docker-compose.yml

@@ -36,7 +36,7 @@ services:
 
   db:
 
-    image: postgres:13.6
+    image: postgres:15.3
     restart: always
     volumes:
       - /srv/keycloak/db:/var/lib/postgresql/data

webserver/docker_matrix/templates/docker-compose.yml

@@ -10,7 +10,7 @@ services:
 
   db:
 
-    image: postgres:13.11
+    image: postgres:15.3
     restart: always
     volumes:
       - /srv/matrix/db:/var/lib/postgresql/data