[Infra] Fix hosts total count query (#212749)

Fixes [#212745](https://github.com/elastic/kibana/issues/212745)

## Summary

Fix for the hosts total count query, which was not correctly filtering
hosts from system integration and APM

<img width="584" alt="image"
src="https://github.com/user-attachments/assets/05c3b244-3a0f-425a-82db-3498c1a6dbb7"
/>


### How to test
- Connect Kibana to an edge cluster
- Navigate to Infrastructure > Hosts
- The total number of items on the table should be equal to the number
in the hosts count KPI

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

x-pack/solutions/observability/plugins/infra/server/routes/infra/lib/host/get_hosts_count.ts

@@ -25,8 +25,14 @@ export async function getHostsCount({
 }) {
   assertQueryStructure(query);
 
+  const apmDocumentSources = await apmDataAccessServices?.getDocumentSources({
+    start: from,
+    end: to,
+  });
+
   const documentsFilter = await getDocumentsFilter({
     apmDataAccessServices,
+    apmDocumentSources,
     from,
     to,
   });
@@ -37,8 +43,15 @@ export async function getHostsCount({
     track_total_hits: false,
     query: {
       bool: {
-        filter: [query, ...rangeQuery(from, to)],
-        should: [...documentsFilter],
+        filter: [
+          query,
+          ...rangeQuery(from, to),
+          {
+            bool: {
+              should: [...documentsFilter],
+            },
+          },
+        ],
       },
     },
     aggs: {