chore: use if TYPE_CHECKING: blocks (#2866)

bin/inspect_all_known_projects.py

@@ -24,8 +24,9 @@ This will cache the results to all_known_setup.yaml; you can reprint
 the results without the `--online` setting.
 """
 
+from __future__ import annotations
+
 import ast
-from collections.abc import Iterable, Iterator
 from pathlib import Path
 
 import click
@@ -35,6 +36,10 @@ from rich import print
 
 from cibuildwheel.projectfiles import Analyzer
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from collections.abc import Iterable, Iterator
+
 DIR = Path(__file__).parent.resolve()