Enable GPT-4o code completion (copilot)

[ThisGuyCodes]

This blog post: https://github.blog/changelog/2025-02-18-new-gpt-4o-copilot-code-completion-model-now-available-in-public-preview-for-copilot-in-vs-code/

I'd love to use the newer completion model. A lot of the AI work in zed seems focused on the chat, but I don't really use the chat....

[garymjr]

I'm also interested in this. I looks like the crate is still using an older version of the copilot LSP. copilot.vim can be referenced for the latest version. I'm also not clear after looking through the code how we would pass the required settings to the copilot LSP since it doesn't appear to be configurable using the normal lsp key in settings.json

[sircoderin]

I implemented this and waiting for a review.