chore: update renovate bot configuration (#204)

renovate.json

@@ -1,7 +1,8 @@
 {
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
   "extends": [
-    "config:base"
+    "config:base",
+    "helpers:pinGitHubActionDigests"
   ],
   "packageRules": [
     {
@@ -10,10 +11,7 @@
       "automerge": true
     },
     {
-      "fileMatch": [
-        "^(workflow-templates|\\.github\\/workflows)\\/[^/]+\\.ya?ml$",
-        "(^|\\/)action\\.ya?ml$"
-      ],
+      "matchManagers": ["github-actions"],
       "automerge": true
     }
   ]