This is checked redundantly, which creates confusion.

• check_texture_dimension_size chooses a sample_limit based on the dimension, and then validates the sample count does not exceed the limit.
• create_texture has a separate block of checks that apply when sample_count > 1.

Reading the code for the latter gives the impression that a 3D multisampled texture with depth 1 would be incorrectly accepted, but it is disallowed by the former.