Type annotation corrections

[tekktrik]

Was working on adafruit_atecc and noticed it used some of the functions here, and that it meant some of the type annotations needed to be updated.

1. Type annotations for arguments made as general as possible (and still correct) - for example, adafruit_atecc uses some functions with bytearray where it was typed as bytes, and looking at the functions the correct type should be circuitpython_typing.ReadableBuffer
2. unhexlify should also take the buffer type, which matches CPython behavior, and taking a look at the function it will still work so not changes are needed to how it works
3. Blinka 7.2.3 adds circuitpython_typing, so no need to explicitly require other than pinning it as minimum Blinka version. Including it explicitly is an option instead, though, if we didn't want to force Blinka update.

[FoamyGuy]

Looks good to me. Thanks @tekktrik

tested the simpletest successfully on PyGamer.