chore(deps): update actions/cache action to v5

Author: renovate[bot]

.github/workflows/gh-deploy.yml

@@ -49,7 +49,7 @@ jobs:
         run: echo "cache_id=$(date --utc '+%V')" >> $GITHUB_ENV
 
       - name: Save cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           key: mkdocs-material-${{ env.cache_id }}
           path: .cache