Skip major updates to actions/setup-node

Author: colinrotherham

.github/dependabot.yml

@@ -90,6 +90,12 @@ updates:
     reviewers:
       - alphagov/design-system-developers
 
+    ignore:
+      # Ignore major updates (causes delays in `~/.npm` cache restore time)
+      # See pull request: https://github.com/alphagov/govuk-frontend/pull/4558
+      - dependency-name: actions/setup-node
+        update-types: ['version-update:semver-major']
+
     # Schedule run every Monday, local time
     schedule:
       interval: weekly