Remove CPATH from macOS SDK configuration

CPATH may cause clang++ to find incompatible header definitions.
Keep SDKROOT for SDK path resolution but remove CPATH to avoid
header conflicts.

Author: pocc

.github/workflows/gh_actions_macos.yml

@@ -11,7 +11,6 @@ jobs:
       - name: Configure macOS SDK for clang-tidy
         run: |
           echo "SDKROOT=$(xcrun --show-sdk-path)" >> $GITHUB_ENV
-          echo "CPATH=$(xcrun --show-sdk-path)/usr/include" >> $GITHUB_ENV
       - name: Install 5 hooks, python3, llvm already includes clang-tidy, clang-format
         run: brew install uncrustify cppcheck oclint iwyu
       - name: Fix OCLint dylib paths