Revert the use of typing_extensions in py3.8+

mgorny · Byron · commit 62131f3905ac · 2021-12-01T08:09:19.000+08:00
The original change requiring py3.10 TypeGuard (and matching
typing_extensions) has been reverted, so revert the requirement
on typing_extensions as well.
diff --git a/requirements.txt b/requirements.txt
@@ -1,2 +1,2 @@
 gitdb>=4.0.1,<5
-typing-extensions>=3.7.4.3;python_version<"3.10"
+typing-extensions>=3.7.4.3;python_version<"3.8"

Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,2 @@`
`1`	`1`	`gitdb>=4.0.1,<5`
`2`		`-typing-extensions>=3.7.4.3;python_version<"3.10"`
	`2`	`+typing-extensions>=3.7.4.3;python_version<"3.8"`