Fix typo in setup.py (#13487)

Co-authored-by: Ewa Marek <ewa.marek@nanoporetech.com>
Co-authored-by: Diego Molina <diemol@users.noreply.github.com>

py/setup.py

@@ -72,7 +72,7 @@
                  'selenium.webdriver.support', ],
     'include_package_data': True,
     'install_requires': [
-        "typing_extension~= 4.9",
+        "typing_extensions~= 4.9",
         "urllib3[socks]>=1.26,<3",
         "trio~=0.17",
         "trio-websocket~=0.9",