Rollup merge of #143118 - Kivooeo:tf15, r=tgross35

`tests/ui`: A New Order [15/N]

> [!NOTE]
>
> Intermediate commits are intended to help review, but will be squashed prior to merge.

Some `tests/ui/` housekeeping, to trim down number of tests directly under `tests/ui/`. Part of rust-lang/rust#133895.

r? `@jieyouxu`

Author: dianqk