upgrade toml to 0.8

[syphar]

One important breaking change is in the changelog:

Serialization and deserialization of tuple variants has changed from being an array to being a table with the key being the variant name and the value being the array

toml-rs/toml@toml-v0.7.8...toml-v0.8.0

I think that our usage of toml in web::crate_details should be fine with the change, I'm not 100% sure about our usage in the metadata crate.

I would love to have a second pair of eyes on the change.

[Nemo157]

Should be fine, we're not using serde::Deserialize with toml on any enums so that change won't affect us.