Update toml requirement from 0.5 to 0.8

Updates the requirements on [toml](https://github.com/toml-rs/toml) to permit the latest version.
- [Commits](toml-rs/toml@toml_datetime-v0.5.0...toml-v0.8.8)

---
updated-dependencies:
- dependency-name: toml
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

neqo-crypto/Cargo.toml

@@ -15,7 +15,7 @@ log = {version = "0.4.0", default-features = false}
 bindgen = {version = "0.64", default-features = false, features= ["runtime"]}
 serde = "1.0"
 serde_derive = "1.0"
-toml = "0.5"
+toml = "0.8"
 mozbuild = {version = "0.1", optional = true}
 
 [dev-dependencies]