Run CircleCI with the HEAD sha, not the base (#14625)

* Run CircleCI with the HEAD sha, not the base
* Different solution

.circleci/config.yml

@@ -50,8 +50,8 @@ references:
     run:
       name: Update jsonnet
       command: |
-       export PR_NUMBER=$(git ls-remote origin "pull/*/head" | grep -F -f <(git rev-parse HEAD) | awk -F'/' '{print $3}')
        export SHA=$(git rev-parse --short HEAD)
+       export PR_NUMBER=$(git ls-remote origin "pull/*/head" | grep -F -f $SHA | awk -F'/' '{print $3}')
        python -c "fname = 'dockers/tpu-tests/tpu_test_cases.jsonnet' ; data = open(fname).read().replace('{PYTORCH_VERSION}', '$XLA_VER')
        data = data.replace('{PYTHON_VERSION}', '$PYTHON_VER').replace('{PR_NUMBER}', '$PR_NUMBER').replace('{SHA}', '$SHA') ; open(fname, 'w').write(data)"
        cat dockers/tpu-tests/tpu_test_cases.jsonnet

.github/workflows/ci-circleci.yml

@@ -23,6 +23,9 @@ jobs:
   trigger-circleci:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
       - uses: CircleCI-Public/trigger-circleci-pipeline-action@v1.0.5
         env:
           CCI_TOKEN: ${{ secrets.CCI_TOKEN }}

dockers/tpu-tests/tpu_test_cases.jsonnet

@@ -28,7 +28,7 @@ local tputests = base.BaseTest {
       cd lightning
       echo $PWD
       git ls-remote --refs origin
-      git fetch origin "refs/pull/{PR_NUMBER}/head:pr/{PR_NUMBER}" && git checkout "pr/{PR_NUMBER}"
+      git fetch origin "refs/pull/{PR_NUMBER}/head"
       git checkout {SHA}
       export PACKAGE_NAME=pytorch
       export FREEZE_REQUIREMENTS=1