Auto merge of rust-lang#123339 - onur-ozkan:optimize-tidy-check, r=Mark-Simulacrum

optimize tidy check on `src/tools/tidy/src/issues.txt`

This change applies to the following:

- Handles `is_sorted` in the first iteration without needing a second.
- Fixes line sorting on `--bless`.
- Reads `issues.txt` as str rather than making it part of the source code.

Fixes rust-lang#123002

Author: bors