GL problems on Wayland, Fedora 40

[jwahlstrand]

I upgraded my laptop (with built-in Intel GPU) to Fedora 40 and found that GTK4's GL backend is not working. Setting the EGL vendorlib directories does not fix the issue as it did in Fedora 39 and Ubuntu. Workarounds include 1. using X11 or 2. GTK4's cairo renderer, by setting GSK_RENDERER=cairo.