feat: option to build directly with uv (#2322)

* feat: option to build directly with uv

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

tests: add uv to tests

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

fix: uv doesn't pick special Pythons at the top of the path

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

fix: set uv build constraints too

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

fix: uv doesn't support PyPy 3.8

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

tests: add pyproject.toml for failing test

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

Revert "tests: add pyproject.toml for failing test"

This reverts commit 619bde368a67dfdd8f02dc33a1525c27bc8cbe91.

tests: skip uv output test

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* tests: uv was in the wrong fixture

Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

* fix: from @trim21

Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

* tests: improve skipping

Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

* fix: some fixes from copilot review

Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

test/test_android.py

@@ -128,7 +128,7 @@ def test_frontend_good(tmp_path, build_frontend_env):
     assert wheels == [f"spam-0.1.0-cp313-cp313-android_21_{native_arch.android_abi}.whl"]
 
 
-@pytest.mark.parametrize("frontend", ["pip"])
+@pytest.mark.parametrize("frontend", ["pip", "uv"])
 def test_frontend_bad(frontend, tmp_path, capfd):
     new_c_project().generate(tmp_path)
     with pytest.raises(CalledProcessError):