Rollup merge of #137885 - klensy:tidy-triagebot, r=jieyouxu

tidy: add triagebot checks

Validates triagebot.toml to have existing paths:

`[mentions."*"]` sections, i.e.
```toml
[mentions."compiler/rustc_const_eval/src/"]
```
or
```toml
[assign.owners]
"/.github/workflows" = ["infra-ci"]
```
or

```toml
trigger_files = [
 "src/librustdoc/html/static/js/search.js",
 "tests/rustdoc-js",
 "tests/rustdoc-js-std",
 ]
```
Looked at #137876 and implemented check.

Author: matthiaskrgr