Content-Type header is not set while constructing Request object

[orionmiz]

Describe the bug
Content-Type header is not set while constructing Request object.

To Reproduce

const request = new Request(TEST_URL, { method: "POST", body: "Hello World" })
console.log(request.headers.get("Content-Type")) // null

Expected behavior
Above request.headers.get("Content-Type") should return "text/plain;charset=UTF-8"

Additional context
I'll fix it.

[capricorn86]

Your fix has been released and is available here:
https://github.com/capricorn86/happy-dom/releases/tag/v10.10.0