remove constraint on typing-extensions version (#20)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Brendan <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -1,3 +1,3 @@
 adafruit-circuitpython-typing
 pytest
-typing-extensions~=4.0
+typing-extensions