deps(actions): bump actions/cache from 4 to 5

Bumps [actions/cache](https://github.com/actions/cache) from 4 to 5.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v4...v5)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/build-deploy-site.yml

@@ -31,7 +31,7 @@ jobs:
           pip install pyyaml requests
       
       - name: Restore LeetCode API cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         with:
           path: .leetcode_cache.json
           key: leetcode-cache-latest

.github/workflows/update-leetcode-grid.yml

@@ -22,7 +22,7 @@ jobs:
 
       - name: Restore last processed commit
         id: last_commit_cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: .last_leetcode_commit
           key: leetcode-last-commit
@@ -65,7 +65,7 @@ jobs:
           pip install pyyaml requests
 
       - name: Restore LeetCode API cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         with:
           path: .leetcode_cache.json
           key: leetcode-cache-${{ github.run_id }}
@@ -78,7 +78,7 @@ jobs:
 
       - name: Save updated cache
         if: always()
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         with:
           path: .leetcode_cache.json
           key: leetcode-cache-${{ github.run_id }}