grafana afs : remove centos 8 volume tracking

These volumes have been removed as CentOS 8 (not stream) has been
retired.

Change-Id: I431f90583ce6d6cb80d3244e7488b75463314e25

grafana/afs.yaml

@@ -822,23 +822,6 @@ dashboard:
               refId: C
               hide: true
 
-        - title: Centos 8 ARM64
-          type: graph
-          span: 4
-          yaxes:
-            - format: deckbytes
-              min: 0
-            - format: deckbytes
-              min: 0
-          targets:
-            - target: "alias(stats.gauges.afs.afs01_dfw_openstack_org.vol.mirror_wheel_cent8a64.used, 'Used')"
-              refId: A
-            - target: "alias(stats.gauges.afs.afs01_dfw_openstack_org.vol.mirror_wheel_cent8a64.quota, 'Quota')"
-              refId: B
-            - target: "divideSeries(stats.gauges.afs.afs01_dfw_openstack_org.vol.mirror_wheel_cent8a64.used, #B)"
-              refId: C
-              hide: true
-
         - title: Centos 8 Stream ARM64
           type: graph
           span: 4
@@ -962,24 +945,6 @@ dashboard:
               refId: C
               hide: true
 
-
-        - title: Centos 8 x86_64
-          type: graph
-          span: 4
-          yaxes:
-            - format: deckbytes
-              min: 0
-            - format: deckbytes
-              min: 0
-          targets:
-            - target: "alias(stats.gauges.afs.afs01_dfw_openstack_org.vol.mirror_wheel_cent8x64.used, 'Used')"
-              refId: A
-            - target: "alias(stats.gauges.afs.afs01_dfw_openstack_org.vol.mirror_wheel_cent8x64.quota, 'Quota')"
-              refId: B
-            - target: "divideSeries(stats.gauges.afs.afs01_dfw_openstack_org.vol.mirror_wheel_cent8x64.used, #B)"
-              refId: C
-              hide: true
-
         - title: Centos 8 Stream x86_64
           type: graph
           span: 4
@@ -1055,15 +1020,6 @@ dashboard:
           format: dateTimeFromNow
           valueFontSize: "50%"
 
-        - title: Centos 8 ARM64
-          type: singlestat
-          valueName: current
-          span: 2
-          targets:
-            - target: "scale(stats.gauges.afs.afs01_dfw_openstack_org.vol.mirror_wheel_cent8a64_readonly.creation, 1000)"
-          format: dateTimeFromNow
-          valueFontSize: "50%"
-
         - title: Centos 8 Stream ARM64
           type: singlestat
           valueName: current
@@ -1132,15 +1088,6 @@ dashboard:
           valueFontSize: "50%"
 
 
-        - title: Centos 8 x86_64
-          type: singlestat
-          valueName: current
-          span: 2
-          targets:
-            - target: "scale(stats.gauges.afs.afs01_dfw_openstack_org.vol.mirror_wheel_cent8x64_readonly.creation, 1000)"
-          format: dateTimeFromNow
-          valueFontSize: "50%"
-
         - title: Centos 8 Stream x86_64
           type: singlestat
           valueName: current