dependabot: Ignore major PatternFly and sass updates

Copied from our other projects.

.github/dependabot.yml

@@ -36,6 +36,15 @@ updates:
         patterns:
           - "@xterm/*"
 
+    ignore:
+      # https://github.com/cockpit-project/cockpit/issues/21151
+      - dependency-name: "sass"
+        versions: ["1.80.x", "2.x"]
+
+      # needs to be done in Cockpit first
+      - dependency-name: "@patternfly/*"
+        update-types: ["version-update:semver-major"]
+
   - package-ecosystem: "github-actions"
     directory: "/"
     open-pull-requests-limit: 3