tests: Don't rely on facts when setting become

They won't be available if the play is first, and hence no facts have been
gather in previous play(s), e.g. due to --start-at-task

.ci/ansible_tests.py

@@ -66,14 +66,16 @@ with ci_lib.Fold('job_setup'):
             for container in containers
         )
 
-        for distro, hostnames in distros.items():
+        for distro, hostnames in sorted(distros.items(), key=lambda t: t[0]):
             fp.write('\n[%s]\n' % distro)
             fp.writelines('%s\n' % name for name in hostnames)
 
-        for family, hostnames in families.items():
+        for family, hostnames in sorted(families.items(), key=lambda t: t[0]):
             fp.write('\n[%s]\n' % family)
             fp.writelines('%s\n' % name for name in hostnames)
 
+        fp.write('\n[linux:children]\ntest-targets\n')
+
     ci_lib.dump_file(inventory_path)
 
     if not ci_lib.exists_in_path('sshpass'):

tests/ansible/regression/issue_776__load_plugins_called_twice.yml

@@ -2,7 +2,7 @@
 ---
 - name: regression/issue_776__load_plugins_called_twice.yml
   hosts: test-targets
-  become: "{{ ansible_facts.pkg_mgr not in ['homebrew'] }}"
+  become: "{{ groups.linux is defined and inventory_hostname in groups.linux }}"
   gather_facts: yes
   tags:
     - issue_776