Revisit the hacky requirements.txt approach in ci.yml

[nathanjmcdougall]

I think uv may have matured since this hack was imagined, rendering it unnecessary:

usethis-python/.github/workflows/ci.yml

Lines 31 to 34 in b1df02b

	- name: Setup dependencies
	run: |
	uv export --resolution ${{ matrix.resolution }} > requirements.txt
	uv pip install --system --break-system-packages -r requirements.txt

[nathanjmcdougall]

Similar idea here:

www.github.com/python-attrs/attrs/pull/1409/files

[nathanjmcdougall]

Blocked by www.github.com/astral-sh/python-build-standalone/issues/508

[nathanjmcdougall]

Waiting for a new release here:
https://github.com/CodSpeedHQ/valgrind-codspeed/releases

[nathanjmcdougall]

It looks like despite the new release it's still not resolved. So still waiting on astral-sh/python-build-standalone#508

[nathanjmcdougall]

Unfortunately, #334 needs to be reverted because it's breaking codecov. We need to try again but make sure codecov is working.