Update policy scaling recommendation (#1563)

* Update policy scaling recommendation

* Add note about spaces support

Author: kilfoyle

docs/en/ingest-management/agent-policies.asciidoc

@@ -556,4 +556,6 @@ The unenroll task runs every ten minutes, and it unenrolls a maximum of one thou
 [[agent-policy-scale]]
 == Policy scaling recommendations
 
-A single instance of {fleet} supports a maximum of 500 {agent} policies. If more policies are configured, UI performance might be impacted.
+A single instance of {fleet} supports a maximum of 1000 {agent} policies. If more policies are configured, UI performance might be impacted. The maximum number of policies is not affected by the number of spaces in which the policies are used.
+
+If you are using {agent} with link:{serverless-docs}[{serverless-full}], the maximum supported number of {agent} policies is 500.

docs/en/ingest-management/fleet/fleet-server-scaling.asciidoc

@@ -232,7 +232,9 @@ of these operations.
 
 **{agent} policies**
 
-A single instance of {fleet} supports a maximum of 500 {agent} policies. If more policies are configured, UI performance might be impacted.
+A single instance of {fleet} supports a maximum of 1000 {agent} policies. If more policies are configured, UI performance might be impacted. The maximum number of policies is not affected by the number of spaces in which the policies are used.
+
+If you are using {agent} with link:{serverless-docs}[{serverless-full}], the maximum supported number of {agent} policies is 500.
 
 **{agents}**