chore: don't use otak/fix-1.0.3 branch for proteus as a dev-dependency

There's no obvious reason why proteus dev-dependency should differ from
the regular one.

This also lets us drop the last remaining reference to sodiumoxide,
hopefully speeding up builds a bit.

Author: istankovic

Cargo.lock

@@ -86,7 +86,6 @@ rstest = "0.26"
 rstest_reuse = "0.7"
 env_logger = "0.11"
 futures-util = { workspace = true, features = ["std", "alloc"] }
-proteus-traits = { workspace = true }
 async-trait.workspace = true
 wire-e2e-identity = { workspace = true, features = ["builder"] }
 web-time.workspace = true
@@ -97,9 +96,6 @@ smol.workspace = true
 smol-macros.workspace = true
 macro_rules_attribute.workspace = true
 
-[target.'cfg(not(target_family = "wasm"))'.dev-dependencies]
-proteus = { git = "https://github.com/wireapp/proteus", branch = "otak/fix-1.0.3" }
-
 [target.'cfg(not(target_family = "wasm"))'.dev-dependencies.criterion]
 version = "0.8"
 features = ["async_smol", "async_futures", "html_reports"]