shutil.unpack_archive returns bogus ReadError exceptions when input is not found or inaccessible

Bug report

$ python -c 'import shutil; shutil.unpack_archive("./enoent")'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib64/python3.11/shutil.py", line 1311, in unpack_archive
    raise ReadError("Unknown archive format '{0}'".format(filename))
shutil.ReadError: Unknown archive format './enoent'

$ python -c 'import shutil; shutil.unpack_archive("/root/inaccessible")'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib64/python3.11/shutil.py", line 1311, in unpack_archive
    raise ReadError("Unknown archive format '{0}'".format(filename))
shutil.ReadError: Unknown archive format '/root/inaccessible'

The generic exception makes it handle to handle the error programatically, and the message is also very confusing to the user. Instead, the function should just propagate the detailed exception it got internally. Compare with open:

$ python -c 'open("./enoent")'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
FileNotFoundError: [Errno 2] No such file or directory: './enoent'

$ python -c 'open("/root/inaccessible")' 
Traceback (most recent call last):
  File "<string>", line 1, in <module>
PermissionError: [Errno 13] Permission denied: '/root/inaccessible'

Your environment

python3-3.11.0-1.fc37.x86_64

Linked PRs

• gh-155587

Start in shutil.py around line 1311 and reproduce the missing-file and inaccessible-path commands shown in the report. Check the existing unpack_archive behavior and related tests, if present; done means these inputs expose their detailed filesystem exceptions rather than a generic ReadError.