[CI] Another attempt to fix lint task (#9885)

Author: aelovikov-intel

.github/workflows/sycl_precommit.yml

@@ -39,7 +39,6 @@ jobs:
     steps:
     - uses: actions/checkout@v3
       with:
-        ref: ${{ github.event.pull_request.merge_commit_sha }}
         sparse-checkout: |
           devops/actions/cached_checkout
     - name: 'PR commits + 2'
@@ -48,10 +47,7 @@ jobs:
       with:
         path: src
         fetch-depth: ${{ env.PR_FETCH_DEPTH }}
-        # clang-format uses github.event.pull_request.base.sha that has the top
-        # of the base branch, not the merge base. As such, checkout the merge
-        # commit instead of github.event.pull_request.head.sha.
-        ref: ${{ github.event.pull_request.merge_commit_sha }}
+        ref: ${{ github.event.pull_request.head.sha }}
         cache_path: "/__w/repo_cache/"
         merge: false
     - name: Run clang-format

devops/actions/clang-format/action.yml

@@ -12,13 +12,16 @@ runs:
     shell: bash {0}
     run: |
       git config --global --add safe.directory ${{ inputs.path }}
-      git -C ${{ inputs.path }} clang-format ${{ github.event.pull_request.base.sha }}
+      # TODO: Should we just drop fetch-depth in the cached checkout?
+      base=$(git -C ${{ inputs.path }} merge-base ${{ github.event.pull_request.base.sha }} HEAD)
+      echo "::group::Debug"
+      echo "HEAD:"
+      git -C ${{ inputs.path }} log -1 HEAD
+      echo "Merge-base:"
+      git -C ${{ inputs.path }} log -1 $base
+      echo "::endgroup::"
+      git -C ${{ inputs.path }} clang-format $base
       git -C ${{ inputs.path }} diff > ./clang-format.patch
-  - name: Debug
-    shell: bash
-    run: |
-      git -C ${{ inputs.path }} log ${{ github.event.pull_request.base.sha }}..HEAD
-      git -C ${{ inputs.path }} diff ${{ github.event.pull_request.base.sha }}..HEAD
   # Add patch with formatting fixes to CI job artifacts
   - uses: actions/upload-artifact@v1
     with: