fix: use f-string instead of .format() in show_test_item

Modernize the code by replacing .format() with f-string syntax.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

src/_pytest/runner.py

@@ -158,7 +158,7 @@ def show_test_item(item: Item) -> None:
     tw.write(item.nodeid)
     used_fixtures = sorted(getattr(item, "fixturenames", []))
     if used_fixtures:
-        tw.write(" (fixtures used: {})".format(", ".join(used_fixtures)))
+        tw.write(f" (fixtures used: {', '.join(used_fixtures)})")
     tw.flush()