limit agent list total count to 10k (#135026)

(cherry picked from commit d61253a)

x-pack/plugins/fleet/public/applications/fleet/sections/agents/agent_list_page/index.tsx

@@ -631,7 +631,7 @@ export const AgentListPage: React.FunctionComponent<{}> = () => {
         pagination={{
           pageIndex: pagination.currentPage - 1,
           pageSize: pagination.pageSize,
-          totalItemCount: totalAgents,
+          totalItemCount: Math.min(totalAgents, SO_SEARCH_LIMIT),
           pageSizeOptions,
         }}
         isSelectable={true}