Add proxy setting retrieving for chat open ai node, to fix https://github.com/n8n-io/n8n/issues/10901

[jasonliusz]

Summary

Add proxy setting retrieving for chat open ai node, to fix issue 10901

Related Linear tickets, Github issues, and Community forum posts

I investigated through the source code, confirm that open ai node does NOT respect any http_proxy setting, when it call langchain's openai client.
The issue happens, because HTTP "fetch" api does not respect http_proxy. It is required to set the Proxy Agent explicitly. Other HTTP nodes(i.e. Google Calendar) works because they are using AXIOS for HTTP invoking instead.

The original issue is posed @ issue 10901

I have verified it via ProxyMan. the https traffic of open ai can be seen in the screenshot:

Review / Merge checklist

• PR title and summary are descriptive. (conventions)
• Docs updated or follow-up ticket created.
• Tests included.
• PR Labeled with release/backport (if the PR is an urgent fix that needs to be backported)

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[Joffcom]

Hey @jasonliusz,

Thanks for the PR, We have created "GHC-1048" as the internal reference to get this reviewed.

One of us will be in touch if there are any changes needed, in most cases this is normally within a couple of weeks but it depends on the current workload of the team.