Ensure typing-extensions is installed when building docs.

Author: domdfcoding

doc-source/requirements.txt

@@ -15,3 +15,4 @@ sphinx-tabs>=1.1.13
 sphinx-toolbox>=2.13.0b3
 sphinxemoji>=0.1.6
 toctree-plus>=0.5.0
+typing-extensions>=3.10.0.0

pypi_json/typehints.py

@@ -37,8 +37,6 @@
 if typing.TYPE_CHECKING:
 	# 3rd party
 	from typing_extensions import TypedDict
-elif hasattr(typing, "TypedDict"):  # pragma: no cover (<py38)
-	TypedDict = typing.TypedDict  # noqa: TYP006
 else:  # pragma: no cover
 	try:
 		# 3rd party