Use Ruff for from __future__ import annotations checks (#10910)

tests/check_consistent.py

@@ -83,9 +83,6 @@ def check_test_cases() -> None:
         bad_test_case_filename = 'Files in a `test_cases` directory must have names starting with "check_"; got "{}"'
         for file in testcase_dir.rglob("*.py"):
             assert file.stem.startswith("check_"), bad_test_case_filename.format(file)
-            with open(file, encoding="UTF-8") as f:
-                lines = {line.strip() for line in f}
-            assert "from __future__ import annotations" in lines, "Test-case files should use modern typing syntax where possible"
 
 
 def check_no_symlinks() -> None: