There was one test in the volume render test folder that made use of the ocean sim modifier to add some detail. This lead to test failures when building Blender without ocean sim. To fix this issue, this commit applies the ocean sim modifier. This means it's no longer used, but the render results are the same, meaning there is no need to update the reference images. Pull Request: https://projects.blender.org/blender/blender/pulls/138729