zed: Remove unnecessary #[allow(non_snake_case)] attribute (#21030)

This PR removes the `#[allow(non_snake_case)]` attribute from the `zed`
crate, as it wasn't actually doing anything.

Release Notes:

- N/A

crates/zed/src/main.rs

@@ -1,5 +1,3 @@
-// Allow binary to be called Zed for a nice application menu when running executable directly
-#![allow(non_snake_case)]
 // Disable command line from opening on release mode
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]