tests: fully type the test suite (#2794)

* tests: fully type the test suite

* chore: require more typing

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

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Signed-off-by: Henry Schreiner <henryfs@princeton.edu>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

test/test_before_all.py

@@ -1,5 +1,6 @@
 import subprocess
 import textwrap
+from pathlib import Path
 
 import pytest
 
@@ -29,7 +30,7 @@ project_with_before_build_asserts = test_projects.new_c_project(
 )
 
 
-def test(tmp_path):
+def test(tmp_path: Path) -> None:
     project_dir = tmp_path / "project"
     project_with_before_build_asserts.generate(project_dir)
 
@@ -61,7 +62,7 @@ def test(tmp_path):
     assert set(actual_wheels) == set(expected_wheels)
 
 
-def test_failing_command(tmp_path):
+def test_failing_command(tmp_path: Path) -> None:
     project_dir = tmp_path / "project"
     test_projects.new_c_project().generate(project_dir)
 
@@ -75,7 +76,7 @@ def test_failing_command(tmp_path):
         )
 
 
-def test_cwd(tmp_path):
+def test_cwd(tmp_path: Path) -> None:
     project_dir = tmp_path / "project"
     test_projects.new_c_project().generate(project_dir)