feat(renovate): GitHub cache for Renovate repo cache

.github/workflows/renovate.yaml

@@ -15,6 +15,11 @@ on:
         description: Log-Level
         default: debug
         required: false
+      cache:
+        description: Use Renovate cache from GitHub repo's cache?
+        type: choice
+        default: "enabled"
+        options: ["enabled", "disabled", "reset"]
       paths:
         description: Paths to run Renovate on. Comma separated without spaces for multiple.
         required: false
@@ -46,6 +51,8 @@ env:
   RENOVATE_AUTODISCOVER_FILTER: "${{ github.repository }}" # this is to prevent forks from running Renovate against upstream repo
   RENOVATE_USERNAME: "${{ secrets.BOT_USERNAME }}[bot]"
   RENOVATE_GIT_AUTHOR: "${{ secrets.BOT_USERNAME }} <${{ secrets.BOT_API_ID }}+${{ secrets.BOT_USERNAME }}[bot]@users.noreply.github.com>" # get $BOT_API_ID from `curl -s 'https://api.github.com/users/$(BOT_USERNAME)%5Bbot%5D' | yq .id`
+  RENOVATE_REPOSITORY_CACHE: "enabled"
+  GH_CACHE_DIR: "/tmp/renovate/cache/renovate/repository"
 
 jobs:
   renovate:
@@ -69,9 +76,21 @@ jobs:
         run: |
           echo "RENOVATE_DRY_RUN=${{ github.event.inputs.dryRun || env.RENOVATE_DRY_RUN }}" >> "${GITHUB_ENV}"
           echo "LOG_LEVEL=${{ github.event.inputs.logLevel || env.LOG_LEVEL }}" >> "${GITHUB_ENV}"
+          echo "RENOVATE_REPOSITORY_CACHE=${{ github.event.inputs.cache || env.RENOVATE_REPOSITORY_CACHE }}" >> "${GITHUB_ENV}"
           if [[ ! -z "${{ github.event.inputs.paths }}" ]]; then echo "RENOVATE_INCLUDE_PATHS=${{ github.event.inputs.paths }}" >> "${GITHUB_ENV}"; fi
           if [[ ! -z "${{ github.event.inputs.managers }}" ]]; then echo "RENOVATE_ENABLED_MANAGERS=${{ github.event.inputs.managers }}" >> "${GITHUB_ENV}"; fi
 
+      - name: Renovate Cache
+        id: renovate-cache
+        uses: actions/cache@v4
+        if: github.event.inputs.cache != 'disabled'
+        continue-on-error: true
+        with:
+          path: "${{ env.GH_CACHE_DIR }}"
+          key: "renovate-cache-${{ runner.os }}-${{ github.run_id }}"
+          restore-keys: |
+            renovate-cache-${{ runner.os }}
+
       - name: Renovate
         uses: renovatebot/github-action@936628dfbff213ab2eb95033c5e123cfcaf09ebb # v41.0.5
         with: