fix: don't poll HTTP on startup to prevent dependency cycle between framework dev server and Netlify Dev

[Skn0tt]

Summary

Resolves https://linear.app/netlify/issue/COM-550/cannot-boot-ntl-dev-on-astro-project-using-functions-and-edge

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[ascorbic]

There's nothing Astro-specific in the issue though. Which other frameworks should do the same?

[Skn0tt]

I guess every framework that might use passthrough requests. Do we have a list of them?

[ascorbic]

These are normal Netlify functions or edge functions, so basically any framework.

[Skn0tt]

Hmm, that feels weird. We have HTTP as a polling strategy for almost all of our frameworks - wouldn't they all suffer from this problem? Alternatively, what if we change the polling mechanism in CLI so that it starts up the function server, even if the framework dev server isn't fully running yet?

[ascorbic]

Yes, they would all suffer from this. To be clear: it's quite a niche issue, which is why it hasn't come up before afaik. It's a site that calls one of its own functions when rendering the index page via SSR. I'd say that's an anti-pattern, tbh

[Skn0tt]

We discussed this a bit more in https://linear.app/netlify/issue/COM-550/cannot-boot-ntl-dev-on-astro-project-using-functions-and-edge#comment-4b579375, and there seems to be consensus that there's no reason to check HTTP when polling for the framework server. So I removed the HTTP polling strategy from all frameworks in c84ec68.

[ascorbic]

Some overly-specific tests need updating

[Skn0tt]

Updated them in 2320bf6.

[ascorbic]

I'd change the title before merging, to be more specific about what's changed