[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

src/_pytest/capture.py

@@ -177,7 +177,7 @@ def name(self) -> str:
     def mode(self) -> str:
         # TextIOWrapper doesn't expose a mode, but at least some of our
         # tests check it.
-        assert hasattr(self.buffer, 'mode')
+        assert hasattr(self.buffer, "mode")
         return cast(str, self.buffer.mode.replace("b", ""))