Replace cargo-cranky with workspace lints (#4413)

Replace `cargo-cranky` (which has served us well) with workspace lints

examples/custom_3d_glow/Cargo.toml

@@ -7,6 +7,9 @@ edition = "2021"
 rust-version = "1.76"
 publish = false
 
+[lints]
+workspace = true
+
 
 [dependencies]
 eframe = { workspace = true, features = [

examples/custom_3d_glow/src/main.rs

@@ -1,5 +1,7 @@
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")] // hide console window on Windows in release
+#![allow(rustdoc::missing_crate_level_docs)] // it's an example
 #![allow(unsafe_code)]
+#![allow(clippy::undocumented_unsafe_blocks)]
 
 use eframe::{egui, egui_glow, glow};