Rollup merge of #128965 - Zalathar:no-pat, r=Nadrieril

Remove `print::Pat` from the printing of `WitnessPat`

After the preliminary work done in #128536, we can now get rid of `print::Pat` entirely.

- First, we introduce a variant `PatKind::Print(String)`.
- Then we incrementally remove each other variant of `PatKind`, by having the relevant code produce `PatKind::Print` instead.
- Once `PatKind::Print` is the only remaining variant, it becomes easy to remove `print::Pat` and replace it with `String`.

There is more cleanup that I have in mind, but this seemed like a natural stopping point for one PR.

r? ```@Nadrieril```

Author: workingjubilee