Fixed unclosed file warning

[radarhere]

Pillow/Tests/test_image.py

Lines 232 to 236 in 60b5131

	def test_unknown_extension(self, tmp_path: Path) -> None:
	im = hopper()
	temp_file = tmp_path / "temp.unknown"
	with pytest.raises(ValueError):
	im.save(temp_file)

raises an unclosed file warning - https://github.com/python-pillow/Pillow/actions/runs/14155530774/job/39654267057?pr=8844#step:6:5623

This is because hopper() is just returning an opened image.

Pillow/Tests/helper.py

Lines 248 to 257 in 60b5131

	def hopper(mode: str | None = None) -> Image.Image:
	# Use caching to reduce reading from disk, but return a copy
	# so that the cached image isn't modified by the tests
	# (for fast, isolated, repeatable tests).
	if mode is None:
	# Always return fresh not-yet-loaded version of image.
	# Operations on not-yet-loaded images are a separate class of errors
	# that we should catch.
	return Image.open("Tests/images/hopper.ppm")