[APM] Fix stack trace syntax highlight (elastic#205187)

fixes: [elastic#204957](elastic#204957)

## Summary

This PR fixes the stack trace syntax highlight

<img width="1452" alt="image"
src="https://github.com/user-attachments/assets/ee076fc6-c901-4e8f-a760-8c85a5470a26"
/>

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>
(cherry picked from commit a78f616)

x-pack/solutions/observability/plugins/apm/server/routes/errors/get_error_groups/get_error_sample_details.ts

@@ -28,6 +28,7 @@ import {
   TRANSACTION_ID,
   ERROR_STACK_TRACE,
   SPAN_ID,
+  SERVICE_LANGUAGE_NAME,
 } from '../../../../common/es_fields/apm';
 import { environmentQuery } from '../../../../common/utils/environment_query';
 import { ApmDocumentType } from '../../../../common/document_type';
@@ -83,6 +84,7 @@ export async function getErrorSampleDetails({
     SPAN_ID,
     AGENT_VERSION,
     PROCESSOR_NAME,
+    SERVICE_LANGUAGE_NAME,
     ERROR_CULPRIT,
     ERROR_STACK_TRACE,
     ERROR_EXC_MESSAGE,

x-pack/test/api_integration/deployment_agnostic/apis/observability/apm/mobile/errors/generate_data.ts

@@ -33,6 +33,9 @@ export async function generateData({
 }) {
   const serviceGoProdInstance = apm
     .service({ name: serviceName, environment: 'production', agentName: 'swift' })
+    .defaults({
+      'service.language.name': 'swift',
+    })
     .instance('instance-a');
 
   const interval = '1m';

x-pack/test/api_integration/deployment_agnostic/apis/observability/apm/mobile/errors/group_id_samples.spec.ts

@@ -138,6 +138,10 @@ export default function ApiTest({ getService }: DeploymentAgnosticFtrProviderCon
           it('displays correct error culprit info', () => {
             expect(errorSampleDetailsResponse.error.error.culprit).to.equal('Error culprit 1');
           });
+
+          it('displays correct language name', () => {
+            expect(errorSampleDetailsResponse.error.service.language?.name).to.equal('swift');
+          });
         });
       });