remove deprecated & empty block_devices group

Author: sjpb

environments/common/inventory/groups

@@ -13,7 +13,7 @@ login
 control
 compute
 
-[eessi:children]
+[eessi]
 # Hosts on which EESSI stack should be configured
 
 [hpctests:children]
@@ -79,9 +79,6 @@ cluster
 # Hosts to install firewalld on - see ansible/roles/filewalld
 fail2ban
 
-[block_devices]
-# Superset of hosts to configure filesystems on - see ansible/roles/block_devices/README.md
-
 [basic_users]
 # Add `openhpc` group to add slurm users via creation of users on each node.