Update pip-tools version and 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
    ? ^

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

(Now closed) issue on pip-tools: jazzband/pip-tools#2252

Testing:

aws-cli % python3 -m pytest tests/backends/build_system/functional/test_lock_files.py
========================================================================= test session starts ==========================================================================
platform darwin -- Python 3.13.5, pytest-7.4.0, pluggy-1.6.0
rootdir: ***/aws-cli
configfile: pyproject.toml
plugins: xdist-3.1.0, cov-4.1.0
collected 2 items                                                                                                                                                      

tests/backends/build_system/functional/test_lock_files.py ..                                                                                                     [100%]

========================================================================== 2 passed in 11.64s ==========================================================================

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

[hssyoo]

Assuming CI passes 🏆