update clang format (#332)

Author: andiwand

.github/workflows/format.yml

@@ -11,14 +11,16 @@ jobs:
     runs-on: ubuntu-22.04
 
     steps:
-      - run: clang-format --version
+      - run: sudo apt install clang-format-15
+
+      - run: clang-format-15 --version
 
       - name: checkout
         uses: actions/checkout@v2
 
       - name: apply clang-format
         run: |
           FILES=$( find . -type f \( -iname \*.h -o -iname \*.cpp \) )
-          clang-format-12 --style=file -i $FILES
+          clang-format-15 --style=file -i $FILES
 
       - run: git diff --exit-code --name-only