Rename ansible groups to use _ instead of - (#7552)

* rename ansible groups to use _ instead of -

k8s-cluster -> k8s_cluster
k8s-node -> k8s_node
calico-rr -> calico_rr
no-floating -> no_floating

Note: kube-node,k8s-cluster groups in upgrade CI
      need clean-up after v2.16 is tagged

* ensure old groups are mapped to the new ones

contrib/network-storage/glusterfs/glusterfs.yml

@@ -15,7 +15,7 @@
   roles:
     - { role: glusterfs/server }
 
-- hosts: k8s-cluster
+- hosts: k8s_cluster
   roles:
     - { role: glusterfs/client }
 

contrib/network-storage/glusterfs/inventory.example

@@ -23,15 +23,15 @@
 # node2
 # node3
 
-# [kube-node]
+# [kube_node]
 # node2
 # node3
 # node4
 # node5
 # node6
 
-# [k8s-cluster:children]
-# kube-node
+# [k8s_cluster:children]
+# kube_node
 # kube_control_plane
 
 # [gfs-cluster]