Also enable python 3.9

Author: dudoslav

.github/workflows/build-wheels.yml

@@ -23,7 +23,7 @@ jobs:
           - [macos-13, macosx_x86_64]
           - [macos-13, macosx_arm64]
           - [windows-2022, win_amd64]
-        python: ["cp310", "cp311", "cp312"]
+        python: ["cp39", "cp310", "cp311", "cp312"]
 
     steps:
       - uses: actions/checkout@v3