Update typing extensions to allow v4

Author: kclowes

setup.py

@@ -86,7 +86,7 @@
         "pywin32>=223;platform_system=='Windows'",
         "requests>=2.16.0,<3.0.0",
         # remove typing_extensions after python_requires>=3.8, see web3._utils.compat
-        "typing-extensions>=3.7.4.1,<4;python_version<'3.8'",
+        "typing-extensions>=4.0.0,<5;python_version<'3.8'",
         "websockets>=9.1,<10",
     ],
     python_requires='>=3.6,<4',