`zipfile.Path.read_text` & `.open` methods with a positional `encoding` arg causes a TypeError

[gpshead]

This is a regression from 3.9 behavior seen in Python 3.10.

zipfile.Path.read_text passes *args and **kwargs to it's own open() method, but in 3.10+ is also blindly sets kwargs["encodings"] to a value. So code that was previously passing an encoding as a positional argument now sees:

 File "/<stdlib>/zipfile.py", line 2362, in read_text
 with self.open('r', *args, **kwargs) as strm:
 File "/<stdlib>/zipfile.py", line 2350, in open
 return io.TextIOWrapper(stream, *args, **kwargs)
TypeError: Failed to construct dataset imagenet2012: argument for TextIOWrapper() given by name ('encoding') and position (2)

3.10's Lib/zipfile.py (and main's Lib/zipfile/_path.py) contain:

 def read_text(self, *args, **kwargs):
 kwargs["encoding"] = io.text_encoding(kwargs.get("encoding")) # <-- new in 3.10, source of bug
 with self.open('r', *args, **kwargs) as strm:
 return strm.read()

As this is a regression, we should avoid setting that value in kwargs when "encodings" not in kwargs to match 3.9 and earlier behavior.

TODO list:

• @jaraco will port the change to zipp.

Linked PRs

• gh-101144: Allow open and read_text encoding to be positional. #101145
• [3.11] gh-101144: Allow zipfile.Path .open & .read_text encoding to be positional #101179
• [3.10] gh-101144: Allow zipfile.Path .open & .read_text encoding to be positional (GH-101179) #101182

[gpshead]

(and note that 3.10 is probably closed to bugfixes)

[gpshead]

Workaround for users, always pass encoding to read_text as a keyword encoding= argument rather than the first positional argument.