Auto merge of #10603 - epage:toml, r=ehuss

chore: Upgrade toml_edit

### What does this PR try to resolve?

This upgrades toml_edit and tries to make future upgrades easier.  To do this, it officially adds `toml_edit` to the public API but this will let RLS use these errors and stay up-to-date without manual intervention.

### How should we test and review this PR?

The main question is if we should have toml_edit in the API

### Additional information

See https://github.com/rust-lang/rls/pull/1764