fix: faster CLI on Python 3.15

[henryiii]

This makes running cibuildwheel --help or cibuildwheel --print-build-indentifiers around 3-4x faster on Python 3.15a7 by making imports lazy. If using uv on a first run (like with uvx), this likely is even more, since it doesn't pre-compile .pyc files by default.

I used my flake8-lazy package (post here) to come up with the
__lazy_modules__ lists, and GPT 5 (due to the 0x token usage) in VSCode's copilot to apply the lists to the files.

I restored from __future__ import annotations, but maybe I didn't need to, since they are not resolved on 3.14+. I might try without too later. I think it's fine, but #2799 and #2798 were exposed while trying this. Will minimize the diff after those.

Edit: used the new --apply feature of flake8-lazy to create this instead.

Benchmark 1: .venv/bin/python3.14 -m cibuildwheel -h Time (mean ± σ): 250.7 ms ± 5.2 ms [User: 201.2 ms, System: 28.9 ms] Range (min … max): 243.1 ms … 258.9 ms 11 runs Benchmark 1: .venv/bin/python3.15 -m cibuildwheel -h Time (mean ± σ): 59.4 ms ± 4.6 ms [User: 48.0 ms, System: 8.5 ms] Range (min … max): 55.6 ms … 80.3 ms 49 runs 

Benchmark 1: .venv/bin/python3.14 -m cibuildwheel --print-build-identifiers Time (mean ± σ): 249.9 ms ± 4.3 ms [User: 199.5 ms, System: 27.4 ms] Range (min … max): 242.8 ms … 258.3 ms 11 runs Benchmark 1: .venv/bin/python3.15 -m cibuildwheel --print-build-identifiers Time (mean ± σ): 64.8 ms ± 1.0 ms [User: 53.5 ms, System: 9.0 ms] Range (min … max): 63.4 ms … 68.0 ms 41 runs 

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Here's the version with @hugovk's CPython fix (thanks to @hugovk!):

$ hyperfine --warmup 10 \ "./python.exe -m cibuildwheel --help" \ "PYTHON_LAZY_IMPORTS=none ./python.exe -m cibuildwheel --help" Benchmark 1: ./python.exe -m cibuildwheel --help Time (mean ± σ): 56.2 ms ± 1.5 ms [User: 46.5 ms, System: 8.6 ms] Range (min … max): 53.6 ms … 62.3 ms 50 runs Benchmark 2: PYTHON_LAZY_IMPORTS=none ./python.exe -m cibuildwheel --help Time (mean ± σ): 173.9 ms ± 2.3 ms [User: 151.8 ms, System: 19.9 ms] Range (min … max): 169.9 ms … 177.5 ms 17 runs Summary ./python.exe -m cibuildwheel --help ran 3.09 ± 0.09 times faster than PYTHON_LAZY_IMPORTS=none ./python.exe -m cibuildwheel --help 

[hugovk]

henryiii#17 defers more imports to be 1.4x faster than this PR and 4x faster than upstream main.