rustdoc: remove tuple link on round braces

This is 682889fb06591c4245422b73b005c5d8ae2d0cad but for tuples. The
reasoning is the same:

* This commit also changes it so that tuples with all-generic elements still
  link to the primitive.tuple.html page, just like slices. So there still
  plenty of on-ramps for anybody who doesn't know about it.
* It's too hard to see when round braces are a separate link from the type
  inside of them.
* It's too hard to click even if you do notice them.

0 files changed, 0 insertions, 0 deletions