Try running coverage only under 3.9!?

tox.ini

@@ -27,7 +27,7 @@ commands =
     mypy: mypy tests/typing_example.py
     mypy: mypy src/attrs/__init__.pyi src/attr/__init__.pyi src/attr/_typing_compat.pyi src/attr/_version_info.pyi src/attr/converters.pyi src/attr/exceptions.pyi src/attr/filters.pyi src/attr/setters.pyi src/attr/validators.pyi
 
-[testenv:py3{8,10,13}-tests]
+[testenv:py3{9,10,13}-tests]
 dependency_groups = cov
 # Python 3.6+ has a number of compile-time warnings on invalid string escapes.
 # PYTHONWARNINGS=d makes them visible during the tox run.
@@ -41,7 +41,7 @@ commands = coverage run -m pytest {posargs}
 # Keep base_python in-sync with .python-version-default
 base_python = py313
 # Keep depends in-sync with testenv above that has the cov dependency group.
-depends = py3{8,10,13}-tests
+depends = py3{9,10,13}-tests
 skip_install = true
 dependency_groups = cov
 commands =