respect that other error watcher may want to filter comparison-overlap errors

Author: tyralla

mypy/messages.py

@@ -1632,6 +1632,8 @@ def dangerous_comparison(self, left: Type, right: Type, kind: str, ctx: Context)
         # respective types of the current iteration here so that we can report the error
         # later if it is persistent over all iteration steps:
         for watcher in self.errors.get_watchers():
+            if watcher._filter:
+                return
             if isinstance(watcher, IterationErrorWatcher):
                 watcher.iteration_dependent_errors.nonoverlapping_types[-1][
                     (ctx.line, ctx.column, ctx.end_line, ctx.end_column, kind)

test-data/unit/check-narrowing.test

@@ -2476,7 +2476,7 @@ while True:
 # flags: --strict-equality
 
 for y in [1.0]:
-    if y is not None or y != "None":  # E: Non-overlapping equality check (left operand type: "float", right operand type: "Literal['None']")
+    if y is not None or y != "None":
         ...
 
 [builtins fixtures/primitives.pyi]