chore(deps): update actions/checkout action to v2.4.2

.github/workflows/docs.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout 🛎️
-        uses: actions/checkout@v2.3.1 # If you're using actions/checkout@v2 you must set persist-credentials to false in most cases for the deployment to work correctly.
+        uses: actions/checkout@v2.4.2 # If you're using actions/checkout@v2 you must set persist-credentials to false in most cases for the deployment to work correctly.
         with:
           persist-credentials: false