Move test_package away from on-disc test fixtures

The tests in this module do not care about the content of the wheel.

Author: dnicolodi

tests/test_package.py

@@ -117,7 +117,7 @@ def test_package_signed_name_is_correct():
 
 
 def test_package_add_attestations(tmp_path, test_wheel):
-    package = package_file.PackageFile.from_filename(test_wheel, None)
+    package = package_file.PackageFile.from_filename(str(test_wheel), None)
 
     assert package.attestations is None