Infra: Fix Python 3.9 on CI (#3763)

Author: hugovk

.github/workflows/test.yml

@@ -39,6 +39,13 @@ jobs:
         - "windows-latest"
         - "macos-latest"
         - "ubuntu-latest"
+        # Python 3.9 is on macos-13 but not macos-latest (macos-14-arm64)
+        # https://github.com/actions/setup-python/issues/696#issuecomment-1637587760
+        exclude:
+        - { python-version: "3.9", os: "macos-latest" }
+        include:
+        - { python-version: "3.9", os: "macos-13" }
+
 
     steps:
       - uses: actions/checkout@v4