test: since 62434e7 we don't need to account for .tox

Author: nedbat

tests/helpers.py

@@ -396,11 +396,6 @@ def all_our_source_files() -> Iterator[tuple[Path, str]]:
     Produces a stream of (filename, file contents) tuples.
     """
     cov_dir = Path(__file__).parent.parent
-    if ".tox" in cov_dir.parts:
-        # We are in a tox-installed environment, look above the .tox dir to
-        # also find the uninstalled source files.
-        cov_dir = Path(os.fspath(cov_dir).partition(".tox")[0])
-
     # To run against all the files in the tox venvs:
     #   for source_file in cov_dir.rglob("*.py"):
     for sub in [".", "benchmark", "ci", "coverage", "lab", "tests"]: