Drop testing under Python 3.9 to fix CI

Author: oprypin

.github/workflows/ci.yml

@@ -21,11 +21,11 @@ jobs:
             os: windows-latest
           - python: '3.11'
             os: ubuntu-latest
-          - python: '3.10'
+          - python: '3.11'
             os: macos-latest
-          - python: '3.9'
+          - python: '3.10'
             os: windows-latest
-          - python: '3.9'
+          - python: '3.10'
             os: ubuntu-latest
             versions: minimal
     runs-on: ${{matrix.os}}