Simplify clang-format workflow by removing matrix

Author: actboy168

.github/workflows/clang-format.yml

@@ -8,11 +8,7 @@ on:
     - master
 jobs:
   clang-format:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [ubuntu-latest, ubuntu-slim]
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
       - run: sudo apt-get install -y clang-format-15