[CI] enable code-format-helper for .cl files

In clang-format, OpenCL .cl file uses default C++ formatting.
There are many pull-requests in libclc project that change OpenCL files.
It is beneficial to enable clang-format for them in CI.

Author: wenju-he

llvm/utils/git/code-format-helper.py

@@ -186,7 +186,7 @@ def filter_changed_files(self, changed_files: List[str]) -> List[str]:
         filtered_files = []
         for path in changed_files:
             _, ext = os.path.splitext(path)
-            if ext in (".cpp", ".c", ".h", ".hpp", ".hxx", ".cxx", ".inc", ".cppm"):
+            if ext in (".cpp", ".c", ".h", ".hpp", ".hxx", ".cxx", ".inc", ".cppm", ".cl"):
                 filtered_files.append(path)
             elif ext == "" and self.should_include_extensionless_file(path):
                 filtered_files.append(path)