gh-48511: Make pwd and grp expose inner errors

[simaoafonso-pwt]

Distinguish between the case when the user/group does not exist and error conditions.
If the user does not exit, raise KeyError as now, for errors raise OSError.

Based on arhadthedev@46c34b6

• Issue: The pwd module doesn't distinguish between errors and no user #48511

[ghost]

All commit authors signed the Contributor License Agreement.

[github-actions]

This PR is stale because it has been open for 30 days with no activity.

[simaoafonso-pwt]

Rebased to the latest main branch, there were some conflicts.

[simaoafonso-pwt]

Rebased to the latest main branch, there were some conflicts.

It seems the CI failure is unrelated.

[simpleprogrammer2]

Rebased to the latest main branch, there were some conflicts.

It seems the CI failure is unrelated.

Test failed due error type change.

ERROR: test_expanduser_pwd (test.test_posixpath.PosixPathTest.test_expanduser_pwd)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/runner/work/cpython/cpython/Lib/test/test_posixpath.py", line 339, in test_expanduser_pwd
    self.assertIsInstance(posixpath.expanduser("~foo/"), str)
                          ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
  File "/Users/runner/work/cpython/cpython/Lib/posixpath.py", line 269, in expanduser
    pwent = pwd.getpwnam(name)
FileNotFoundError: [Errno 2] No such file or directory is this failure related to this change

cpython/Lib/posixpath.py

Line 270 in 206788a

except KeyError:

Because pwd.getpwnam("foo") now raises FileNotFoundError (a subclass of OSError) instead of KeyError, the except KeyError: block in expanduser() fails to catch it, causing the FileNotFoundError to propagate up and fail test_expanduser_pwd.