chore: replace dockerfile renovate config with what's working in the …

…rhdh-operator repo, so we get dockerfile updates for the release-1.y branches too (#2185)

Signed-off-by: Nick Boldt <nboldt@redhat.com>

.github/renovate.json

@@ -4,12 +4,17 @@
     ":gitSignOff",
     ":rebaseStalePrs",
     "group:allNonMajor",
+    "docker:disableMajor",
     "default:pinDigestsDisabled",
     ":automergeBranch"
   ],
   "labels": [
     "kind/dependency upgrade"
   ],
+  "baseBranches": [
+    "main",
+    "/^release-1\\..*/"
+  ],
   "npm": {
     "minimumReleaseAge": "1 day"
   },
@@ -32,19 +37,33 @@
       "dependencyDashboardApproval": true,
       "description": "require dashboard approval for all python dependencies due to potential conflicts"
     },
+  "packageRules": [
     {
-      "matchCategories": [
+      "description": "Do NOT generate PRs to pin or apply digests to dockerfiles",
+      "enabled": false,
+      "matchDatasources": [
         "docker"
       ],
-      "digest": {
-        "enabled": false
-      }
+      "matchUpdateTypes": [
+        "pin",
+        "pinDigest",
+        "digest"
+      ],
+      "automerge": false
     },
     {
+      "description": "Do automerge patch updates to dockerfiles",
+      "enabled": true,
       "matchDatasources": [
         "docker"
       ],
-      "groupName": "Docker base images"
+      "matchUpdateTypes": [
+        "patch"
+      ],
+      "additionalBranchPrefix": "dockerfile ",
+      "groupName": "All dockerfile images",      
+      "automerge": true,
+      "pinDigests": false
     },
     {
       "matchDepTypes": [