Revert "[SP] Skybox now uses GL_CLAMP_TO_EDGE"

This reverts commit 4a1f72c974753991de463e589e063c33a15577d3.
Revert "[MP] Skybox now uses GL_CLAMP_TO_EDGE"

This reverts commit 3bd8364d337f8bfdb830c70dea7d6418daa41bae.