Remove unused type: ignore comments

[AlexWaygood]

Looks like there may also be a bunch of unused type: ignore comments in our openpyxl and SQLAlchemy, but there's large open PRs for both of those at the moment, and I don't want to create unnecessary merge conflicts.

Found by applying this diff to my local clone of mypy and then running mypy_test.py with the --warn-unused-ignores option added

diff --git a/mypy/errors.py b/mypy/errors.py
index 2c2c1e5ca..df06d3656 100644
--- a/mypy/errors.py
+++ b/mypy/errors.py
@@ -626,10 +626,7 @@ class Errors:
                 self.has_blockers.remove(path)

     def generate_unused_ignore_errors(self, file: str) -> None:
-        if (
-            is_typeshed_file(self.options.abs_custom_typeshed_dir if self.options else None, file)
-            or file in self.ignored_files
-        ):
+        if file in self.ignored_files:
             return
         ignored_lines = self.ignored_lines[file]
         used_ignored_lines = self.used_ignored_lines[file]

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉