Try to fix up MacOS CI

Author: rocky

.github/workflows/macos.yml

@@ -19,6 +19,10 @@ jobs:
       uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
+    - name: Install ICU dependencies
+      run: |
+        brew install icu4c
+        run: echo "PKG_CONFIG_PATH=$(brew --prefix icu4c)/lib/pkgconfig" >> $GITHUB_ENV
     - name: Install dependencies
       run: |
         brew install llvm