Improve pytest collection time to <2s

[sshane]

Currently it takes ~6-7s with these plugins:

platform linux -- Python 3.11.4, pytest-8.2.1, pluggy-1.5.0
benchmark: 4.0.0 (defaults: timer=time.perf_counter disable_gc=False min_rounds=5 min_time=0.000005 max_time=1.0 calibration_precision=10 warmup=False warmup_iterations=100000)
Using --randomly-seed=3123610973
rootdir: /home/batman/openpilot
configfile: pyproject.toml
testpaths: tools/, common/, system/, selfdrive/
plugins: anyio-4.3.0, timeout-2.3.1, xdist-3.6.1, cpp-2.5.0, cov-5.0.0, mock-3.14.0, forked-1.6.0, dash-2.11.1, benchmark-4.0.0, randomly-3.15.0, subtests-0.12.1, flaky-3.8.1, hypothesis-6.47.5, asyncio-0.23.7, nbmake-1.5.3, repeat-0.9.3
asyncio: mode=Mode.STRICT

============================================================================= 4011 tests collected in 6.46s ==============================================================================

real    0m8.935s
user    0m10.833s
sys     0m2.163s

Verification:

Run time pytest --collect-only in the root openpilot directory and post both the real time and the collection time as reported by pytest (=== 4011 tests collected in 6.61s ===). Include the times before and after your PR.

[BBBmau]

should the time improvement come from not making changes to the testpath?

You can easily improve by being explicit in testpaths. Doesn't seem like that's the point of this bounty if it's that easy.

[sshane]

pytest selfdrive/car/tests --co takes 1.5s on its own.

[renxida]

============ 4172 tests collected in 2.05s ============

running pytest --co today gives the above output.

Perhaps it's time to close this and give the bounty to whoever got this here.

(just tried again. when i delete the cache, it takes 3.76s)