disable digest pinning for our images, since Forgejo cleans them up

Since Forgejo seems to clean up older tag versions, so older digests,
disable digest pinning for our images.
While generally resulting in undeployable config, with ansible-pull the
breakage is especially noticeable.

renovate.json

@@ -28,6 +28,12 @@
       "matchDatasources": ["docker"],
       "matchPackageNames": ["docker.io/pretix/standalone"],
       "versioning": "regex:^(?<major>\\d+\\.\\d+)(?:\\.(?<minor>\\d+))$"
+    },
+    // Since Forgejo seems to clean up older tag versions, so older digests, disable digest pinning for our images.
+    {
+      "matchDatasources": ["docker"],
+      "matchPackageNames": ["git.hamburg.ccc.de/*"],
+      "pinDigests": false
     }
   ],
   "customManagers": [