Tarfile regression

Bug report

Bug description:

The function _get_filtered_attrs in tarfile.py references the special value os.path.ALLOW_MISSING. This is a problem because this value was only introduced in Python 3.14. However, the reference to this value has been backported to earlier supported Python versions. The result is that tarfile.py can throw an exception when being called from Python versions prior to 3.14.

  File "/usr/local/lib/python3.12/tarfile.py", line 845, in data_filter
    new_attrs = _get_filtered_attrs(member, dest_path, True)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/tarfile.py", line 770, in _get_filtered_attrs
    dest_path = os.path.realpath(dest_path, strict=os.path.ALLOW_MISSING)
                                                   ^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'posixpath' has no attribute 'ALLOW_MISSING'

In Python 3.12, the bug first appears in version 3.12.11.

In the Python 3.13 branch, the bug was introduced in 3.13.4, and persists in all subsequent versions.

In Python 3.11, it appears in all versions after and including 3.11.13

And in the Python 3.10 line, 3.10.18 is the first version where this value appears.

Personally, my symptom of this problem is that this bug prevents me from installing common libraries such as numpy because pip uses the tarfile library to unpack the download from PyPI.

CPython versions tested on:

3.12

Operating systems tested on:

Linux

Start in tarfile.py at _get_filtered_attrs, then reproduce the reported data_filter failure on supported Python versions before 3.14. Verify that tarfile operations no longer raise AttributeError for os.path.ALLOW_MISSING and confirm the reported installation scenario is addressed.