I ran `scripts/linux` on Debian Trixie 13. It suggested manually
installing Mold, but [mold](http://packages.debian.org/mold) is packaged
on Debian and so we could install it automatically.

The version packaged there seems to work well enough for `cargo t` to
pass, at least.

## Tested

```
; sudo apt remove mold libstdc++-14-dev
... uninstalls them
; ./script/linux
The following NEW packages will be installed:
  build-essential clang clang-19 clang-tools-19 g++ g++-14 g++-14-x86-64-linux-gnu g++-x86-64-linux-gnu libstdc++-14-dev mold
; cargo t
(passes)
```

Release Notes:

- N/A