Skip GAL buffer numbers (presumed) when allocating 3d viewer buffers Fixes https://gitlab.com/kicad/code/kicad/issues/8915
Paste layers should be clipped in Realistic mode. Verifying that paste doesn't extend beyond the board area should be left to DRC, or non-realistic mode if you need a 3d view of it. Fixes https://gitlab.com/kicad/code/kicad/issues/9460
There's nothing "legacy" about the OpenGL 3D renderer.