add ios build workflow

.github/workflows/main.yml

@@ -131,3 +131,22 @@ jobs:
       - uses: actions/upload-artifact@v3
         with:
           path: plugins/flutter/example/build/app/outputs/flutter-apk/output
+  build_ios:
+      runs-on: macos-latest
+      steps:
+      - uses: actions/checkout@v3
+      - name: Compile and Test
+        run: |
+          git clone https://github.com/leetal/ios-cmake --depth 1
+          cp ios-cmake/ios.toolchain.cmake .
+          mkdir build
+          cd build
+          cmake -G Xcode -DCMAKE_TOOLCHAIN_FILE=../ios.toolchain.cmake -DPLATFORM=OS64 .. -DPK_BUILD_STATIC_LIB=ON -DPK_USE_CJSON=ON -DPK_USE_BOX2D=ON
+          cmake --build . --config Release
+          ls -l
+          cd ..
+          mkdir -p output/ios
+          cp build/Release-iphoneos/libpocketpy.a output/ios/libpocketpy.a
+      - uses: actions/upload-artifact@v3
+        with:
+          path: output