Virtual modules are not supported

[jamesopstad]

Virtual modules are currently not supported. As part of the fix, we should add a virtual-modules playground so we have test coverage.

[jamesopstad]

Investigation has shown that the reason they don't work is this:

vite-plugin-cloudflare/packages/vite-plugin-cloudflare/src/miniflare-options.ts

Lines 304 to 313 in 7c88a10

	// Sometimes Vite fails to resolve built-ins and converts them to "url-friendly" ids
	// that start with `/@id/...`.
	if (moduleId.startsWith('/@id/')) {
	const result = {
	externalize: moduleId.slice('/@id/'.length),
	type: 'builtin',
	} satisfies vite.FetchResult;
	return new MiniflareResponse(JSON.stringify({ result }));
	}

#63 needs resolving but, for now, we will remove this and disable the nodejs_compat tests until we find a better approach.