We test in proto area not in site-packages.

--- cattrs-24.1.2/tox.ini.orig
+++ cattrs-24.1.2/tox.ini
@@ -28,7 +28,7 @@
     COVERAGE_PROCESS_START={toxinidir}/pyproject.toml
 allowlist_externals = pdm
 commands_pre =
-    python -c 'import pathlib; pathlib.Path("{env_site_packages_dir}/cov.pth").write_text("import coverage; coverage.process_startup()")'
+    python -c 'import pathlib; pathlib.Path("cov.pth").write_text("import coverage; coverage.process_startup()")'
 commands =
     coverage run -m pytest tests {posargs:-n auto}
 passenv = CI