Suppress part of an obnoxious warning about disabling coverage (for end-to-end tests).

setup.cfg

@@ -4,6 +4,8 @@ description-file=README.md
 [tool:pytest]
 testpaths = tests
 addopts = --cov-report term-missing:skip-covered --cov=borgmatic --ignore=tests/end-to-end
+filterwarnings = 
+    ignore:Coverage disabled.*:pytest.PytestWarning
 
 [flake8]
 ignore = E501,W503