Merge pull request #65 from jenkinsci/dependabot/github_actions/actions/checkout-2.4.0

Bump actions/checkout from 2.3.4 to 2.4.0

Author: MarkEWaite

.github/workflows/cd.yaml

@@ -43,7 +43,7 @@ jobs:
     if: needs.validate.outputs.should_release == 'true'
     steps:
     - name: Check out
-      uses: actions/checkout@v2.3.4
+      uses: actions/checkout@v2.4.0
       with:
         fetch-depth: 0
     - name: Set up JDK 8