types.Union was renamed to types.UnionType on the HEAD of 3.10 #9512
Description
Describe the bug
Recently, types.Union was renamed to types.UnionType on the HEAD of 3.10 (refs: python/cpython#27342). After this change, sphinx-build has been crashed because of ImportError.
How to Reproduce
$ tox -e py310
Expected behavior
CI has passed.
Your project
N/A
Screenshots
No response
OS
Linux
Python version
HEAD of 3.10
Sphinx version
4.1.x
Sphinx extensions
No response
Extra tools
No response
Additional context
No response