Prefer newest manylinux wheels by sorting expanded platforms

[eloisekp]

Problem

After switching to rules_pycross, we discovered that some packages (e.g. XGBoost) were resolving to the manylinux2014 wheel instead of the manylinux_2_28 wheel on Linux, which led to slower or less optimal builds when the newer wheel is preferred.

• In _expand_manylinux_platforms(), the expanded platform list was ordered with a regular sorted(platforms) .
• So in the environment’s tag list, manylinux2014_x86_64 appeared before manylinux_2_28_x86_64.
• Then pip’s CandidateEvaluator.compute_best_candidate() ranks wheels by Wheel.support_index_min(self._supported_tags): the first compatible tag in the list wins.
• Because manylinux2014 came first, pip always chose the manylinux2014 wheel when both manylinux2014 and manylinux_2_28 wheels were compatible.

Solution

Sort the expanded platforms so newer manylinux variants come first, and use this key in _expand_manylinux_platforms() instead of sorted(platforms).

Example

With some print debugging while building xgboost
Before
compute_best_candidate filters manylinux_2_28 out of being the "best candidate"

Candidates for xgboost: [<InstallationCandidate('xgboost', <Version('3.0.1')>, <Link xgboost-3.0.1-py3-none-manylinux2014_x86_64.whl>)>, <InstallationCandidate('xgboost', <Version('3.0.1')>, <Link xgboost-3.0.1-py3-none-manylinux_2_28_x86_64.whl>)>, <InstallationCandidate('xgboost', <Version('3.0.1')>, <Link xgboost-3.0.1.tar.gz>)>]

Best candidate for xgboost: 'xgboost' candidate (version 3.0.1 at xgboost-3.0.1-py3-none-manylinux2014_x86_64.whl)

After
compute_best_candidate chooses manylinux_2_28 as the "best candidate"

Candidates for xgboost: [<InstallationCandidate('xgboost', <Version('3.0.1')>, <Link xgboost-3.0.1-py3-none-manylinux2014_x86_64.whl>)>, <InstallationCandidate('xgboost', <Version('3.0.1')>, <Link xgboost-3.0.1-py3-none-manylinux_2_28_x86_64.whl>)>, <InstallationCandidate('xgboost', <Version('3.0.1')>, <Link xgboost-3.0.1.tar.gz>)>]

Best candidate for xgboost: 'xgboost' candidate (version 3.0.1 at xgboost-3.0.1-py3-none-manylinux_2_28_x86_64.whl)

Note

I'm not sure if something like this covers all edge cases