add checkout step to read version file

Author: ezhang6811

.github/workflows/application-signals-e2e-test.yml

@@ -25,6 +25,8 @@ jobs:
   upload-main-build:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 #5.0.0
+
       - name: Configure AWS Credentials
         uses: aws-actions/configure-aws-credentials@a03048d87541d1d9fcf2ecf528a4a65ba9bd7838 #5.0.0
         with: