Run pytest with --color=yes to force GitHub Actions logs to have co…

…lor (#3330)

GitHub Actions does not show colour outputs for pytest by default
(pytest-dev/pytest#7443), but it can be
enabled using `--color=yes` flag.

pyproject.toml

@@ -166,7 +166,7 @@ max-args=10
 
 [tool.pytest.ini_options]
 minversion = "6.0"
-addopts = "--verbose --durations=0 --durations-min=0.2 --doctest-modules --mpl --mpl-results-path=results"
+addopts = "--verbose --color=yes --durations=0 --durations-min=0.2 --doctest-modules --mpl --mpl-results-path=results"
 markers = [
     "benchmark: mark a test with custom benchmark settings.",
 ]