⬆️ Updates actions/cache action to v2.1.6

Signed-off-by: Renovate Bot <bot@renovateapp.com>

Author: renovate-bot

.github/workflows/changelog.yml

@@ -20,7 +20,7 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: 3.0
-      - uses: actions/cache@v2.1.4
+      - uses: actions/cache@v2.1.6
         with:
           path: vendor/bundle
           key: ${{ runner.os }}-changelog-gem