Remove empty limestone nodepool providers

Once the builders have a chance to clear out all uploaded images,
this will remove the remaining references in Nodepool. Then
system-config cleanup can proceed.

Change-Id: I69b96b690918a9145d2e7ccbc79968c5341480bb

nodepool/nl02.opendev.org.yaml

@@ -61,18 +61,6 @@ labels:
     min-ready: 0
 
 providers:
-  - name: limestone-regionone
-    region-name: 'RegionOne'
-    cloud: limestone
-    boot-timeout: 120
-    launch-timeout: 300
-    rate: 0.01
-    diskimages: []
-    pools:
-      - name: main
-        max-servers: 0
-        labels: []
-
   - name: inmotion-iad3
     region-name: 'iad3'
     cloud: inmotion

nodepool/nodepool.yaml

@@ -86,12 +86,6 @@ providers:
     rate: 0.001
     diskimages: *provider_diskimages
 
-  - name: limestone-regionone
-    region-name: 'RegionOne'
-    cloud: limestone
-    rate: 0.001
-    diskimages: []
-
   - name: inmotion-iad3
     region-name: 'iad3'
     cloud: inmotion