fix: use renamed action and add Conan init fallback

- Update workflow to use renamed xahau-patch-conan-post-setup action
- Use 'conan config home' to dynamically find settings.yml location
- Add debug logging to see Conan home contents
- Try 'conan config init' if settings.yml doesn't exist
- This should handle fresh Conan installations

.github/workflows/xahau-ga-nix.yml

@@ -251,7 +251,7 @@ jobs:
           conan profile show default
 
       - name: Patch Conan for newer Clang versions
-        uses: ./.github/actions/xahau-patch-conan-clang-versions
+        uses: ./.github/actions/xahau-patch-conan-post-setup
         with:
           compiler-id: ${{ matrix.compiler_id }}