Rollup merge of #73476 - JakobDegen:should_panic_rustdoc, r=GuillaumeGomez

Added tooltip for should_panic code examples

This change adds a tooltip to the documentation for `should_panic` examples. It currently displays identically to `compile_fail` examples, save for the changed text. It may be helpful to change the color that this displays in to make it visually more clear what is going on, but I'm unsure if additional colors wouldn't just be distracting.

I brought this [up on internals](https://internals.rust-lang.org/t/indicating-that-an-example-is-should-panic-in-docs/12544) a few days ago, and there seemed to be a mild positive response to it.