Fix line too long

Author: tusharsadhwani

src/pip/_internal/cli/cmdoptions.py

@@ -182,7 +182,10 @@ class PipOption(Option):
     dest="require_venv",
     action="store_true",
     default=False,
-    help="Allow pip to only run in a virtual environment; exit with an error otherwise.",
+    help=(
+        "Allow pip to only run in a virtual environment; "
+        "exit with an error otherwise."
+    ),
 )
 
 verbose: Callable[..., Option] = partial(