`tarfile` deprecation warning for PEP-706 should set a stacklevel

[AlexWaygood]

Bug report

Bug description:

I just saw the following deprecation warning in the GitHub Actions log for a project I contribute to:

/opt/hostedtoolcache/Python/3.12.2/x64/lib/python3.12/tarfile.py:2221: DeprecationWarning: Python 3.14 will, by default, filter extracted tar archives and reject files or modify their metadata. Use the filter argument to control this behavior.
    warnings.warn(

Unfortunately, the warning doesn't tell me anything about which line in the project is triggering the warning. The warning points to the line in tarfile.py inside the function that has the deprecation warning, rather than the line in my project that's calling the tarfile function in the depreacted way. We should set a stacklevel here to rectify this (I think stacklevel should be set to 3?):

cpython/Lib/tarfile.py

Lines 2245 to 2250 in d5f1139

	import warnings
	warnings.warn(
	'Python 3.14 will, by default, filter extracted tar '
	+ 'archives and reject files or modify their metadata. '
	+ 'Use the filter argument to control this behavior.',
	DeprecationWarning)

Cc. @encukou as the author and implementer of PEP-706

CPython versions tested on:

3.12

Operating systems tested on:

Linux

Linked PRs

• gh-117691: Add an appropriate stacklevel for PEP-706 tarfile deprecation warnings #117872
• [3.12] gh-117691: Add an appropriate stacklevel for PEP-706 tarfile deprecation warnings (GH-117872) #117930