Rollup merge of #141517 - lolbinarycat:rustdoc-doctest-tooltip-ignore-141092, r=notriddle

rustdoc: use descriptive tooltip if doctest is conditionally ignored

fixes rust-lang/rust#141092

here's what it looks like now:
![screenshot](https://github.com/user-attachments/assets/71e679fe-8828-439d-a2ce-b9187ad3aeea)

Author: tgross35