fix(ci): replace drone with gitea actions

docker-compose.yml

@@ -1,6 +1,6 @@
 version: "3"
 services:
   postfixadmin:
-    image: localhost/volkerraschek/postfixadmin:latest
+    image: git.cryptic.systems/volker.raschek/postfixadmin:latest
     ports:
     - 0.0.0.0:8080:80/tcp