arrow

GH-43665: [R] Remove references to bindings vignette (#43889)

### Rationale for this change

The writing-bindings vignette was removed in
https://github.com/apache/arrow/pull/41576#issuecomment-2134327019. It
turns out there were more references to it throughout the docs that I
failed to remove

### What changes are included in this PR?

Deleting x-refs that don't exist anymore.

### Are these changes tested?

Not really

### Are there any user-facing changes?

The docs won't point you at links that 404.
* GitHub Issue: #43665