gitlab-ci: drop most autotools builds

With autotools this close to being not supported anymore, let's not
waste half of the CI cycles on it. The default build will catch most
issues, and the rest can be tested by the old Travis.

Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
15 jobs for !414 with gitlab-ci-drop-autotools in 50 minutes and 3 seconds (queued for 57 minutes and 19 seconds)
detached
Status Job ID Name Coverage
  Containers Build
passed ubuntu #181354

00:00:42

 
  Build+Test
passed autotools #181365

00:17:34

passed meson-clang #181358

00:08:20

passed meson-gallium-clover-llvm #181362

00:03:18

passed meson-gallium-clover-llvm39 #181363

00:03:40

passed meson-gallium-drivers-other #181361

00:04:58

passed meson-gallium-radeonsi #181360

00:04:40

passed meson-gallium-st-other #181364

00:03:07

passed meson-gallium-swr #181359

00:10:10

passed meson-glvnd #181357

00:05:12

passed meson-loader-classic-dri #181356

00:06:39

passed meson-vulkan #181355

00:03:37

passed scons-llvm #181367

00:06:15

passed scons-nollvm #181366

00:04:51

passed scons-swr #181368

00:06:40