add script to retrieve supported Python versions, optionally from package source metadata #589

Job	Run time
test_pyos / Load tox environments	9s
test_default_python / Load tox environments	5s
test_global_override / Load tox environments	5s
test_supported_pythons / Load tox environments	11s
test_libraries / Load tox environments	5s
test_pytest_args / Load tox environments	8s
test_setenv / Load tox environments	7s
test_prereleases / Load tox environments	7s
test_freethreaded / Load tox environments	7s
test_conda / Load tox environments	8s
test_cache_setup / Load tox environments	6s
test_artifact_upload / Load tox environments	5s
test_venv / Load tox environments	6s
test_default_python / matrix.name	0s
test_cache_setup / matrix.name	0s
test_libraries / matrix.name	0s
test_cache_verify	-1s
test_global_override / matrix.name	-1s
test_freethreaded / matrix.name	0s
test_venv / matrix.name	-1s
test_prereleases / matrix.name	-1s
test_artifact_upload / matrix.name	0s
test_artifact_download	0s
test_setenv / matrix.name	0s
test_pytest_args / matrix.name	0s
test_conda / matrix.name	0s
test_pyos / matrix.name	0s
test_supported_pythons / matrix.name	-1s
	1m 24s

Provide feedback