[3.13] gh-140874: Upgrade bundled pip to 25.3 (GH-140876) (gh-140880)

* gh-140874: Upgrade bundled pip to 25.3 (GH-140876)

Upgrade bundled pip to 25.3
(cherry picked from commit d440a0f96c6e87ee93810e0184068e90087af466)

Co-authored-by: Damian Shaw <damian.peter.shaw@gmail.com>

* Update Misc/NEWS.d/next/Library/2025-11-01-00-36-14.gh-issue-140874.eAWt3K.rst

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>

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Co-authored-by: Damian Shaw <damian.peter.shaw@gmail.com>
Co-authored-by: Paul Moore <p.f.moore@gmail.com>
Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>