gitlab-ci: drop deprecated platforms that snuck in when nobody was watching

... even though I did review that commit. My bad :]

Fixes: c56f09124b195c5cbaab ("gitlab-ci: Move classic driver testing to a new meson-classic job")
Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5844>
(cherry picked from commit 4da8323a14b58303b41826382f1951131171da0f)
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 9ad2268..bdb8584 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -724,7 +724,7 @@
       -D glx=dri
       -D gbm=enabled
       -D egl=enabled
-      -D platforms=x11,wayland,drm,surfaceless
+      -D platforms=x11,wayland
     DRI_DRIVERS: "auto"
     EXTRA_OPTION: >
       -D osmesa=classic