Fix typo in GHA nightly build condition (#6158)

s#ref/heads/#refs/heads/#

I should have noticed it while copy-n-pasting the condition. Unfortunately there are no way to test is other than in prod, but nightly builds are still not getting pushed, see https://github.com/pytorch/vision/runs/6860407007?check_suite_focus=true for example

.github/workflows/build-m1-binaries.yml

@@ -79,7 +79,7 @@ jobs:
           name: torchvision-py${{ matrix.py_vers }}-macos11-m1
           path: dist/
       - name: Upload wheel to S3
-        if: ${{ github.event_name == 'push' && (github.event.ref == 'ref/heads/nightly' || startsWith(github.event.ref, 'refs/tags/')) }}
+        if: ${{ github.event_name == 'push' && (github.event.ref == 'refs/heads/nightly' || startsWith(github.event.ref, 'refs/tags/')) }}
         shell: arch -arch arm64 bash {0}
         env:
           AWS_ACCESS_KEY_ID: ${{ secrets.AWS_PYTORCH_UPLOADER_ACCESS_KEY_ID }}
@@ -139,7 +139,7 @@ jobs:
           name: torchvision-py${{ matrix.py_vers }}-macos11-m1-conda
           path: dist/
       - name: Upload package to conda
-        if: ${{ github.event_name == 'push' && (github.event.ref == 'ref/heads/nightly' || startsWith(github.event.ref, 'refs/tags/')) }}
+        if: ${{ github.event_name == 'push' && (github.event.ref == 'refs/heads/nightly' || startsWith(github.event.ref, 'refs/tags/')) }}
         shell: arch -arch arm64 bash {0}
         env:
           CONDA_PYTORCHBOT_TOKEN: ${{ secrets.CONDA_PYTORCHBOT_TOKEN }}