Revert "Update branch-alias to 0.13.x-dev (#193)" (#194)

Author: swissspidy

composer.json

@@ -26,7 +26,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-main": "0.13.x-dev"
+            "dev-main": "0.12.x-dev"
         }
     },
     "minimum-stability": "dev",