gitlab CI: add a job to compare meson and autotools standard installs

Build and install with meson, build and install with autotools and then run
diff to compare the two directory trees. They should be the same.

This does not install the legacy protocols, they're behind a configure switch.
The spec-build is disabled in autotools because we know meson doesn't do that
yet, so no point in comparing those.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
9 jobs for wip/ci-compare-meson in 1 minute and 48 seconds (queued for 3 seconds)
Status Name Job ID Coverage
  Prep
passed container-prep #7868297

00:00:12

 
  Check
passed check formatting #7868298

00:00:09

 
  Build
passed autotools: [] #7868301

00:00:42

passed autotools: [--enable-legacy] #7868302

00:00:40

passed meson: [] #7868299

00:00:10

passed meson: [-Dlegacy=true] #7868300

00:00:11

 
  Test
passed check evdev keysyms #7868305

00:00:09

passed compare meson and autotools #7868304

00:00:43

passed meson from tarball #7868303

00:00:10