mark a couple of typing-only imports as noqa, to appease pyflakes

Since it cannot resolve `import typing as T` in order to figure out that
T.* is doing annotation-worthy stuff.

Since T.cast('Foo') is not actually using Foo except in an annotation
context (due to being a string) it requires extra work to resolve, and
the only thing that would currently work is actually using
'typing.cast'. However, we have decided to not use it except as T...

Since this import is only imported during mypy it's not so bad to noqa
it.

mesonbuild/interpreterbase/interpreterbase.py

@@ -54,7 +54,9 @@ import textwrap
 from functools import wraps
 
 if T.TYPE_CHECKING:
-    from ..interpreter import Interpreter
+    # T.cast is not handled by flake8 to detect quoted annotation use
+    # see https://github.com/PyCQA/pyflakes/pull/632
+    from ..interpreter import Interpreter # noqa
 
 HolderMapType = T.Dict[
     T.Union[

mesonbuild/mlog.py

@@ -22,7 +22,9 @@ from contextlib import contextmanager
 from pathlib import Path
 
 if T.TYPE_CHECKING:
-    from ._typing import StringProtocol, SizedStringProtocol
+    # T.Union is not handled by flake8 to detect quoted annotation use (StringProtocol)
+    # see https://github.com/PyCQA/pyflakes/pull/632
+    from ._typing import StringProtocol, SizedStringProtocol # noqa: F401
 
 """This is (mostly) a standalone module used to write logging
 information about Meson runs. Some output goes to screen,