[Feature Request] Confirm support for Python 3.14

### Describe the solution you'd like

Python 3.14 is now beta: https://www.python.org/downloads/release/python-3140b1/. Please confirm support. If this doesn't include explicitly upgrading CI for fears of it not being stable yet, please open a separate issue to do that in October. Also, consider opening an issue to drop 3.9 support when 3.14 is stable in October.