xwayland/glx: Enable sRGB fbconfigs

We turn this on if the GL underneath us can enable GL_FRAMEBUFFER_SRGB.
We do try to generate both capable and incapable configs, which is to
keep llvmpipe working until the client side gets smarter about its srgb
capabilities.
5 jobs for glx-egl-srgb-fbconfigs in 5 minutes and 23 seconds (queued for 1 second)
Status Job ID Name Coverage
  Docker Image
passed #10379230
debian-buster

00:00:52

 
  Build And Test
passed #10379231
autotools

00:04:31

passed #10379232
meson

00:02:01

passed #10379233
meson-noglamor

00:02:13

passed #10379234
mingw-cross-build

00:00:52