Update build-system requirements in tests to include python-package-folder

This commit modifies the assertions in the test cases to ensure that the build-system section of the pyproject.toml file includes 'python-package-folder' alongside 'hatchling'. This change aligns the tests with the recent enhancements made to the build configuration.

Author: alelom

tests/test_subfolder_build.py

@@ -661,7 +661,7 @@ def test_temporary_pyproject_has_correct_structure(
 
         # Verify build-system section is added (required for hatchling)
         assert "[build-system]" in content
-        assert 'requires = ["hatchling"]' in content
+        assert 'requires = ["hatchling", "python-package-folder"]' in content
         assert 'build-backend = "hatchling.build"' in content
         assert "[tool.hatch.version]" not in content
         assert "[tool.uv-dynamic-versioning]" not in content
@@ -894,7 +894,7 @@ def test_build_system_section_replaces_setuptools(
 
             # Verify build-system section uses hatchling, not setuptools
             assert "[build-system]" in content
-            assert 'requires = ["hatchling"]' in content
+            assert 'requires = ["hatchling", "python-package-folder"]' in content
             assert 'build-backend = "hatchling.build"' in content
             assert "setuptools" not in content or 'build-backend = "setuptools' not in content
 
@@ -929,7 +929,7 @@ def test_build_system_section_with_subfolder_pyproject(
 
         # Verify build-system section is added
         assert "[build-system]" in content
-        assert 'requires = ["hatchling"]' in content
+        assert 'requires = ["hatchling", "python-package-folder"]' in content
         assert 'build-backend = "hatchling.build"' in content
 
         config.restore()