chore(deps): update actions/cache action to v5 (#40)

Author: renovate-bot

.github/workflows/link-checker.yaml

@@ -18,7 +18,7 @@ jobs:
       - uses: actions/checkout@v6
 
       - name: Restore lychee cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         id: restore-cache
         with:
           path: .lycheecache