Remove thiserror from bevy_app (#15779)

# Objective

- Contributes to #15460

## Solution

- Removed `thiserror` from `bevy_app`

crates/bevy_app/Cargo.toml

@@ -29,7 +29,11 @@ bevy_tasks = { path = "../bevy_tasks", version = "0.15.0-dev" }
 
 # other
 downcast-rs = "1.2.0"
-thiserror = "1.0"
+derive_more = { version = "1", default-features = false, features = [
+  "error",
+  "from",
+  "display",
+] }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 ctrlc = "3.4.4"

crates/bevy_app/src/app.rs

@@ -15,11 +15,11 @@ use bevy_ecs::{
 use bevy_utils::tracing::info_span;
 use bevy_utils::{tracing::debug, HashMap};
 use core::{fmt::Debug, num::NonZero, panic::AssertUnwindSafe};
+use derive_more::derive::{Display, Error};
 use std::{
     panic::{catch_unwind, resume_unwind},
     process::{ExitCode, Termination},
 };
-use thiserror::Error;
 
 bevy_ecs::define_label!(
     /// A strongly-typed class of labels used to identify an [`App`].
@@ -32,9 +32,9 @@ pub use bevy_ecs::label::DynEq;
 /// A shorthand for `Interned<dyn AppLabel>`.
 pub type InternedAppLabel = Interned<dyn AppLabel>;
 
-#[derive(Debug, Error)]
+#[derive(Debug, Error, Display)]
 pub(crate) enum AppError {
-    #[error("duplicate plugin {plugin_name:?}")]
+    #[display("duplicate plugin {plugin_name:?}")]
     DuplicatePlugin { plugin_name: String },
 }