[BUG] edge converter overwrites x-forwarded-host with host

[ktKongTong]

Relate: #753,#752

OpenNext currently overwrites x-forwarded-host with result.internalEvent.headers.host

opennextjs-aws/packages/open-next/src/overrides/converters/edge.ts

Lines 62 to 65 in d35f7cc

	headers: {
	...result.internalEvent.headers,
	"x-forwarded-host": result.internalEvent.headers.host,
	},

This means any existing x-forwarded-host is discarded and replaced with the current host value.

This causes problems in Cloudflare Worker:

user request header:

x-forwarded-host: foo
host: bar

plain worker view:

x-forwarded-host: foo
host: bar

opennextjs/cloudflare view:

x-forwarded-host: bar
host: bar

my use case:

better-auth use x-forwarded-host and x-forward-proto to determine baseURL when trustedProxyHeaders enabled

https://better-auth.com/docs/reference/security#trusted-proxy-headers