chore(deps): bump actions/cache from 2 to 4 (#584)

Bumps [actions/cache](https://github.com/actions/cache) from 2 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v2...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/gh-pages.yml

@@ -16,7 +16,7 @@ jobs:
         node-version: '12'
 
     - name: "Cache dependencies"
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: docs/node_modules
         key: ${{ runner.os }}build-node-${{ hashFiles('docs/yarn.lock') }}