build-test-packages: add retries for git clones

It's possible that GitHub might be having issues during a CI run
which results in the clone failing making the entire job fail.

Given that a failure in cloning can easily be retried with no
consequences, let's do that to avoid failing the entire job.

Change-Id: I8d1bad8d453c61ac113a0bab3529392cbffaf75a

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

@@ -132,6 +132,10 @@
     repo: '{{ artg_rdoinfo_repo_url }}'
     dest: '{{ build_repo_dir }}/DLRN/rdoinfo'
     version: 'master'
+  register: _git_clone
+  until: _git_clone is success
+  retries: 3
+  delay: 5
 
 - name: Use local {{ ansible_distribution }} mirror if available
   shell: >