[9.0] [APM] Remove span documents from getServiceAgent function (elastic#236732) (elastic#236944)

# Backport

This will backport the following commits from `main` to `9.0`:
- [[APM] Remove span documents from getServiceAgent function
(elastic#236732)](elastic#236732)

<!--- Backport version: 9.6.6 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sorenlouv/backport)

<!--BACKPORT
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Remove span documents from getServiceAgent function (elastic#236732)\n\n##
Summary\n\ncloses elastic#236249
\n\nAdding the span document in the query negatively impacts the
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Remove span documents from getServiceAgent
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Remove span documents from getServiceAgent function (elastic#236732)\n\n##
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Remove span documents from getServiceAgent function (elastic#236732)\n\n##
Summary\n\ncloses elastic#236249
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Co-authored-by: Katerina <[email protected]>

Author: kibanamachine

x-pack/solutions/observability/plugins/apm/server/routes/services/get_service_agent.ts

@@ -54,12 +54,7 @@ export async function getServiceAgent({
   const params = {
     terminate_after: 1,
     apm: {
-      events: [
-        ProcessorEvent.span,
-        ProcessorEvent.error,
-        ProcessorEvent.transaction,
-        ProcessorEvent.metric,
-      ],
+      events: [ProcessorEvent.error, ProcessorEvent.transaction, ProcessorEvent.metric],
     },
     body: {
       track_total_hits: 1,