Revert "Add clang-format checker GitHub action." (#5746)

Reverts microsoft/DirectXShaderCompiler#5617

.github/workflows/clang-format-checker.yml

@@ -1,34 +0,0 @@
-name: 'PR clang-format checker'
-on:
-  pull_request:
-    types:
-      - opened
-      - edited
-      - synchronize
-      - reopened
-jobs:
-  check-pr-formatting:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          fetch-depth: 0
-      - name: install clang-format
-        run: sudo apt install -y clang-format
-      - run: |
-            echo Comparing $GITHUB_BASE_REF vs HEAD
-            git diff -U0 --no-color origin/$GITHUB_BASE_REF..HEAD | clang-format-diff -p1 | tee format.diff
-            if [ -s "format.diff" ]
-            then 
-              exit 1
-            fi
-      - if: failure()
-        uses: actions/github-script@v6
-        with:
-          script: |
-            github.rest.issues.createComment({
-              issue_number: context.issue.number,
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              body: 'PR contains clang-format violations. See action log for diff.'
-            })