ci(renovate): disable all manager except github-actions (#61)

Reviewed-on: #61
Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Co-committed-by: Timo Behrendt <t.behrendt@t00n.de>

get-images-from-files/test.Dockerfile

@@ -10,4 +10,4 @@ FROM example.com/library/base@sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 ## Short repo:tag (ignored by design; only registry refs are extracted)
 FROM nginx:3.19
 ## With digest only but no registry (ignored)
-FROM nginx@sha256:42f2d24ae18df9b5251d1cc45548085656d2335e9338fd150a24e415462d151f
+FROM nginx@sha256:1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef

renovate.json

@@ -1,13 +1,5 @@
 {
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-  "extends": [
-    "local>t.behrendt/renovate-configs:common",
-    "local>t.behrendt/renovate-configs:action"
-  ],
-  "packageRules": [
-    {
-      "matchManagers": ["dockerfile", "kubernetes", "helmfile", "helm-values"],
-      "ignorePaths": ["get-images-from-files/test*"]
-    }
-  ]
+  "extends": ["local>t.behrendt/renovate-configs:action"],
+  "enabledManagers": "github-actions"
 }