Possible build regression in 3.13.1 with `-latomic` on MIPS

Bug report

Bug description:

Hey! I'm still learning about these things, but I noticed a difference between 3.13.0 and 3.13.1 and want to confirm if this intentional.

In python-build-standalone, we validate the linked libraries after building a distribution. Both the free-threaded and default variants of Python 3.13.1 failed this validation due to a link to atomic on the following target triples:

• mips-unknown-linux-gnu
• mipsel-unknown-linux-gnu

I'm not sure why the inclusion is limited to these targets yet.

I added an exception to our validation for now, but we're concerned about the additional system requirement and would prefer to remove it. I'm not sure what changed, but it looks like there's a relevant news entry linking to https://github.com/python/cpython/issues/125269.

Note that we apply patches to CPython before building, it's possible this is just our bug.

Related:

• https://github.com/python/cpython/issues/125269
• https://github.com/python/cpython/pull/125416
• https://github.com/indygreg/python-build-standalone/issues/410
• https://github.com/indygreg/python-build-standalone/pull/400

CPython versions tested on:

3.13

Operating systems tested on:

Linux

Start by comparing the CPython 3.13.0 and 3.13.1 build changes, then read the linked issue 125269 and pull request 125416. Reproduce the library validation for the MIPS and MIPSel Linux targets and determine whether the libatomic link is intentional. Done means the regression is explained and the unexpected system requirement is removed or documented.