Refactor tests and remove unused imports

- Cleaned up test files by removing unnecessary imports and unused parameters.
- Simplified test functions by eliminating redundant parameterization and consolidating logic.
- Updated test cases to directly use defined values instead of parameterized inputs where applicable.
- Enhanced readability and maintainability of the test code across various test files.

tests/tools/nodes/test_object_normal_rotation.py

@@ -12,7 +12,6 @@ from tools.nodes.common.normal_map import ROTATION_ATTRIBUTE, FACE_ATTRIBUTE, AX
 SYMMETRY_Y_TO_X = Matrix.Rotation(1.5707963267948966, 4, "Z").to_3x3()
 
 
-@pytest.mark.parametrize('image_layer', ['definition', 'asset'], indirect=True)
 @pytest.mark.parametrize('engine', ['CYCLES', 'BLENDER_EEVEE_NEXT'])
 def test_object_normals_follow_rotation_mirror_axis_and_wall_mask(image_layer, engine, tmp_path):
     scene = bpy.context.scene