Simplify git backend server groups.yaml membership

We run many git server backend nodes which may be replaced with new
servers. To simplify the process of adding or replacing git0* servers
stop explicitly listing them in groups.yaml and instead match them on a
glob.

Change-Id: I3dbf814122bbfc508b2a90a5f5a533226fa0bf8f

inventory/groups.yaml

@@ -67,14 +67,7 @@ groups:
   git-loadbalancer:
     - git.openstack.org
   git-server:
-    - git01.openstack.org
-    - git02.openstack.org
-    - git03.openstack.org
-    - git04.openstack.org
-    - git05.openstack.org
-    - git06.openstack.org
-    - git07.openstack.org
-    - git08.openstack.org
+    - git[0-9]*.openstack.org
   grafana:
     - grafana01.openstack.org
     - grafana02.openstack.org
@@ -139,14 +132,7 @@ groups:
     - files02.openstack.org
     - firehose01.openstack.org
     - git.openstack.org
-    - git01.openstack.org
-    - git02.openstack.org
-    - git03.openstack.org
-    - git04.openstack.org
-    - git05.openstack.org
-    - git06.openstack.org
-    - git07.openstack.org
-    - git08.openstack.org
+    - git[0-9]*.openstack.org
     - grafana01.openstack.org
     - grafana02.openstack.org
     - graphite.openstack.org