gitlab-ci: Actually capture Meson logs

Correct the path to the build directory so we can capture Meson logs;
especially useful when tests fail like in #184.

An example of this change having been run with a deliberately-failing
test, capturing the Meson logs, can be found at:
https://gitlab.freedesktop.org/daniels/weston/-/jobs/94623

Signed-off-by: Daniel Stone <daniels@collabora.com>

.gitlab-ci.yml

@@ -80,5 +80,5 @@ build-native-meson:
     name: weston-$CI_COMMIT_SHA-$CI_JOB_ID
     when: always
     paths:
-    - build-meson/meson-logs
+    - build-*/meson-logs
     - prefix-*