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_ssl.py

@@ -1,4 +1,5 @@
 import textwrap
+from pathlib import Path
 
 import pytest
 
@@ -32,7 +33,7 @@ project_with_ssl_tests = test_projects.new_c_project(
 
 
 @pytest.mark.flaky(reruns=2)
-def test(tmp_path):
+def test(tmp_path: Path) -> None:
     # this test checks that SSL is working in the build environment using
     # some checks in setup.py.
     project_dir = tmp_path / "project"