Allow too many arguments (#26375)

This is nearly half of our #allows, and seems like something we happily
break whenever we need

Release Notes:

- N/A

crates/assistant_slash_command/src/assistant_slash_command.rs

@@ -88,7 +88,6 @@ pub trait SlashCommand: 'static + Send + Sync {
     fn accepts_arguments(&self) -> bool {
         self.requires_argument()
     }
-    #[allow(clippy::too_many_arguments)]
     fn run(
         self: Arc<Self>,
         arguments: &[String],