Bump actions/cache from v2.1.3 to v2.1.5 (#8645)

Bumps [actions/cache](https://github.com/actions/cache) from v2.1.3 to v2.1.5.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](https://github.com/actions/cache/compare/v2.1.3...1a9e2138d905efd099035b49d8b7a3888c653ca8)

Signed-off-by: dependabot[bot] <support@github.com>

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

.github/workflows/docs.yml

@@ -19,7 +19,7 @@ jobs:
           ruby-version: ${{ env.RUBY_VERSION }}
       - name: Setup cache for Bundler
         id: cache
-        uses: actions/cache@v2.1.3
+        uses: actions/cache@v2.1.5
         with:
           path: vendor/bundle
           key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}

.github/workflows/third-party.yml

@@ -27,7 +27,7 @@ jobs:
       with:
         ruby-version: 2.7
     - name: Set up Dependencies Cache
-      uses: actions/cache@v2.1.3
+      uses: actions/cache@v2.1.5
       with:
         path: sandbox/vendor/bundle
         key: ubuntu-latest-gems-${{ hashFiles('**/Gemfile.lock') }}