package/python-typing-extensions: update description

Minimum python version is now 3.9, but also it's not really relevant to
mention this in the package description.

Signed-off-by: Marcus Hoffmann <buildroot@bubu1.eu>
Signed-off-by: Julien Olivain <ju.o@free.fr>
(cherry picked from commit 8d1d851d78269383a548e9440146d4f9d16f5e29)
Signed-off-by: Titouan Christophe <titouan.christophe@mind.be>

package/python-typing-extensions/Config.in

@@ -1,6 +1,6 @@
 config BR2_PACKAGE_PYTHON_TYPING_EXTENSIONS
 	bool "python-typing-extensions"
 	help
-	  Backported and Experimental Type Hints for Python 3.5+.
+	  Backported and experimental type hints for Python.
 
 	  https://github.com/python/typing_extensions