Rollup merge of #128692 - tgross35:update-triagebot, r=Mark-Simulacrum

Add a triagebot mention for `library/Cargo.lock`

Since [1], `Cargo.lock` was split into `Cargo.lock` and `library/Cargo.lock`. Update Triagebot to give the same warning for both.

[1]: rust-lang/rust#128534

Author: matthiaskrgr