a2ba481c71
On specific platforms the viewport could be rendered transparent on top of the OS desktop. Mesa adviced us to enable a `EGL_PRESENT_OPAQUE` when its extension exists. Partially fixes #102994; mesa-zink (https://docs.mesa3d.org/drivers/zink.html) still shows transparent viewports. As this PR already improves the situation we it will be merged. Pull Request: https://projects.blender.org/blender/blender/pulls/124395