Do not build projects with '-distgit' in project name

This is required to gate distgit projects with tripleo
jobs[1]. DLRN already builds packages for rpm spec changes,
no need to additionally build using dlrn-build.yml tasks.

[1] https://review.rdoproject.org/r/#/c/18151

Change-Id: Ib86a2e0e6200b00390443fe253abd0c3c0ef775f

roles/build-test-packages/tasks/main.yml

@@ -203,6 +203,7 @@
   include: dlrn-build.yml artg_change={{ item }}
   with_items: '{{ artg_change_list|default([]) }}'
   when:
+    - '"-distgit" not in item.project'
     - item.project not in artg_skipped_projects
     - release in item.branch