fix: remove the _score field (elastic#197197)

Fixes elastic#189624

Before:
![Pasted Graphic
1](https://github.com/user-attachments/assets/7669c66a-339c-40a5-8a20-8d6ca452612c)

After：
![Pasted
Graphic](https://github.com/user-attachments/assets/d4fa2ac6-9be1-4c77-8976-1df568b8aa7a)

---------

Signed-off-by: fangshun <[email protected]>
Co-authored-by: Davis McPhee <[email protected]>

src/plugins/unified_doc_viewer/public/components/doc_viewer_source/source.test.tsx

@@ -103,5 +103,7 @@ describe('Source Viewer component', () => {
     );
     const jsonCodeEditor = comp.find(JsonCodeEditorCommon);
     expect(jsonCodeEditor).not.toBe(null);
+    expect(jsonCodeEditor.props().jsonValue).toContain('_source');
+    expect(jsonCodeEditor.props().jsonValue).not.toContain('_score');
   });
 });

src/plugins/unified_doc_viewer/public/components/doc_viewer_source/source.tsx

@@ -18,6 +18,7 @@ import type { DataView } from '@kbn/data-views-plugin/public';
 import type { DataTableRecord } from '@kbn/discover-utils/types';
 import { ElasticRequestState } from '@kbn/unified-doc-viewer';
 import { isLegacyTableEnabled, SEARCH_FIELDS_FROM_SOURCE } from '@kbn/discover-utils';
+import { omit } from 'lodash';
 import { getUnifiedDocViewerServices } from '../../plugin';
 import { useEsDocSearch } from '../../hooks';
 import { getHeight, DEFAULT_MARGIN_BOTTOM } from './get_height';
@@ -70,7 +71,7 @@ export const DocViewerSource = ({
 
   useEffect(() => {
     if (requestState === ElasticRequestState.Found && hit) {
-      setJsonValue(JSON.stringify(hit.raw, undefined, 2));
+      setJsonValue(JSON.stringify(omit(hit.raw, '_score'), undefined, 2));
     }
   }, [requestState, hit]);