Remove backtracking survey link

Author: pradyunsg

src/pip/_internal/resolution/resolvelib/reporter.py

@@ -28,8 +28,7 @@ def __init__(self) -> None:
                 "This is taking longer than usual. You might need to provide "
                 "the dependency resolver with stricter constraints to reduce "
                 "runtime. If you want to abort this run, you can press "
-                "Ctrl + C to do so. To improve how pip performs, tell us what "
-                "happened here: https://pip.pypa.io/surveys/backtracking"
+                "Ctrl + C to do so."
             ),
         }