The new syntax is nice, but also this avoids the python 3.14 sphinx issues we've been encountering.

I think I prefer this to any of the other options:

• Linking to an older version of the python documentation is non-standard, and gives us another place in the codebase we need to remember to periodically update.
• Ignoring the warnings seems like a bad idea because this is a real issue.
• Switching the code to use the new union syntax everywhere seems like a lot of effort, though we may want to do it in the long term.
• Writing a custom formatter for sphinx_autodoc_typehints would be pretty hacky.