Use toml_edit directly instead of toml

[mo8it]

I replaced the toml crate with toml_edit. The toml crate uses toml_edit under the hood anyway (see https://epage.github.io/blog/2023/01/toml-vs-toml-edit by the author of both crates).
There is one change caused by this move: The display feature of toml_edit is not enabled now which means that we only activate what we use (serde and parse).