Fix mypy violations (with mypy-0.971)

Author: tk0miya

setup.py

@@ -41,7 +41,7 @@
     'lint': [
         'flake8>=3.5.0',
         'isort',
-        'mypy>=0.950',
+        'mypy>=0.971',
         'docutils-stubs',
         "types-typed-ast",
         "types-requests",

sphinx/util/logging.py

@@ -77,7 +77,7 @@ def convert_serializable(records: List[logging.LogRecord]) -> None:
 
         location = getattr(r, 'location', None)
         if isinstance(location, nodes.Node):
-            r.location = get_node_location(location)  # type: ignore
+            r.location = get_node_location(location)
 
 
 class SphinxLogRecord(logging.LogRecord):
@@ -431,7 +431,7 @@ class DisableWarningIsErrorFilter(logging.Filter):
     """Disable WarningIsErrorFilter if this filter installed."""
 
     def filter(self, record: logging.LogRecord) -> bool:
-        record.skip_warningsiserror = True  # type: ignore
+        record.skip_warningsiserror = True
         return True