Go is a statically typed, AOT-compiled language, unlike V8. The kind of task that had countless hours of R&D poured into it for decades, much of it public research and open source code.
I'm not sure how GC is relevant here at all given that JS is also a garbage-collected language.
Go being garbage collected and still beating v8 is one hell of an achievement.
If you need faster Go Http you're using the wrong tool.