Use EGL+GLES workaround for Nvidia X11

We can avoid disabling EGL entirely by forcing Qt to use GLES,
which is not impacted by the black window issue. This lets us
simplify back to EGL everywhere.

app/wm.cpp

@@ -183,10 +183,3 @@ QString WMUtils::getDrmCardOverride()
 
     return QString();
 }
-
-bool WMUtils::isX11EGLSafe()
-{
-    // Nvidia's driver has broken EGL support on X11 and XWayland
-    // https://github.com/moonlight-stream/moonlight-qt/issues/1751
-    return !WMUtils::isRunningNvidiaProprietaryDriverX11();
-}