Fix typo in cURL documentation (#184701)

## Summary

Line 37 already has the ending quote.

## Testing Steps

I ran the same steps as in #182604 and saw that the typo was gone from
the UI. I was able to copy and paste the cURL command directly from the
UI to my terminal and it worked (with or without a pipeline).

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/serverless_search/public/application/components/languages/curl.ts

@@ -32,7 +32,7 @@ export API_KEY="${apiKey}"`,
   },
   iconType: 'curl.svg',
   id: Languages.CURL,
-  ingestData: ({ ingestPipeline }) => `curl -X POST "\$\{ES_URL\}/_bulk?pretty"${
+  ingestData: ({ ingestPipeline }) => `curl -X POST "\$\{ES_URL\}/_bulk?pretty${
     ingestPipeline ? `&pipeline=${ingestPipeline}` : ''
   }" \\
   -H "Authorization: ApiKey "\$\{API_KEY\}"" \\