add source-version-override

Author: benieric

.github/workflows/codebuild-ci.yml

@@ -3,7 +3,7 @@ on:
     pull_request_target:
 
 concurrency:
-    group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+    group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.head_ref }}
     cancel-in-progress: true
 
 permissions:
@@ -24,6 +24,7 @@ jobs:
         uses: aws-actions/aws-codebuild-run-build@v1
         with:
           project-name: sagemaker-python-sdk-ci-codestyle-doc-tests
+          source-version-override: 'pr/${{ github.event.pull_request.number }}'
   unit-tests:
     runs-on: ubuntu-latest
     strategy:
@@ -41,6 +42,7 @@ jobs:
         uses: aws-actions/aws-codebuild-run-build@v1
         with:
           project-name: sagemaker-python-sdk-ci-unit-tests
+          source-version-override: 'pr/${{ github.event.pull_request.number }}'
           env-vars-for-codebuild: |
             PY_VERSION
         env: