Update pip 25.3 lockfiles

[AndrewAsseily]

Description of changes:

A new version of pip (25.3) was released on October 24th, 2025. This is causing the lockfile test to fail since a newer version is allowed in our requirements than the one currently in the lockfiles:

Test: https://github.com/aws/aws-cli/blob/v2/tests/backends/build_system/functional/test_lock_files.py

The test failure shows:

FAILED backends/build_system/functional/test_lock_files.py::test_lock_files_are_up_to_date - AssertionError: assert 'pip==25.3 ...34bb10c083ce8' == 'pip==25.2 ...34bb10c083ce8'

    pip==25.2
    ? ^

    pip==25.3
    ? ^

To resolve this, I used the update lockfiles GitHub Action.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[kdaily]

Looks like updating to pip==25.3 caused an issue with our current use of pip-tools?

Failed test:

https://github.com/aws/aws-cli/actions/runs/19078548801/job/54500658322?pr=9829

Open issue on pip-tools:

jazzband/pip-tools#2252