Merge pull request 'yawhn/revert_postgres_version' (#9253) from yawhn/elreqkey:yawhn/revert_postgres_version into develop

Reviewed-on: https://codeberg.org/calckey/calckey/pulls/9253

dev/docker-compose.yml.example

@@ -30,7 +30,7 @@ services:
 
   db:
     restart: always
-    image: docker.io/postgres:13.9-alpine
+    image: docker.io/postgres:12.2-alpine
     container_name: calckey_db
     networks:
       - network

docker-compose.yml

@@ -31,7 +31,7 @@ services:
 
   db:
     restart: unless-stopped
-    image: docker.io/postgres:13.9-alpine
+    image: docker.io/postgres:12.2-alpine
     container_name: calckey_db
     networks:
       - calcnet