GH-43879: [Go] Remove go related code (#44293)

### Rationale for this change

Go code has been mode to its own repository at https://github.com/apache/arrow-go

### What changes are included in this PR?

Removing the folder `go/` from the https://github.com/apache/arrow repository

### Are these changes tested?

I'll validate on CI there's no failures

### Are there any user-facing changes?

The Go code is no longer present on the Arrow repository.
* GitHub Issue: #43879

Authored-by: Raúl Cumplido <raulcumplido@gmail.com>
Signed-off-by: Raúl Cumplido <raulcumplido@gmail.com>