Fix asset loader registration warning (#11870)

# Objective

When registering and preregistering asset loaders, there would be a
`warn!` if multiple asset loaders use a given extension, and an `info!`
if multiple asset loaders load the same asset type. Since both of these
situations are individually fine, it was decided that these messages
should be removed.

## Solution

Replace both of these messages with a new `warn!` that notes that if
multiple asset loaders share the same asset type _and_ share extensions,
that the loader must be specified in the `.meta` file for those assets
in order to solve the ambiguity. This is a more useful message, since it
notes when a user must take special action / consideration.

crates/bevy_asset/src/server/loaders.rs

@@ -3,7 +3,7 @@ use crate::{
     path::AssetPath,
 };
 use async_broadcast::RecvError;
-use bevy_log::{error, info, warn};
+use bevy_log::{error, warn};
 use bevy_tasks::IoTaskPool;
 use bevy_utils::{HashMap, TypeIdMap};
 use std::{any::TypeId, sync::Arc};
@@ -40,14 +40,15 @@ impl AssetLoaders {
             };
 
         if is_new {
+            let mut duplicate_extensions = Vec::new();
             for extension in loader.extensions() {
                 let list = self
                     .extension_to_loaders
                     .entry(extension.to_string())
                     .or_default();
 
                 if !list.is_empty() {
-                    warn!("duplicate registration for extension `{extension}`.");
+                    duplicate_extensions.push(extension);
                 }
 
                 list.push(loader_index);
@@ -60,8 +61,10 @@ impl AssetLoaders {
                 .entry(loader_asset_type)
                 .or_default();
 
-            if !list.is_empty() {
-                info!("duplicate registration for type `{loader_asset_type_name}`.");
+            let duplicate_asset_registration = !list.is_empty();
+            if !duplicate_extensions.is_empty() && duplicate_asset_registration {
+                warn!("Duplicate AssetLoader registered for Asset type `{loader_asset_type_name}` with extensions `{duplicate_extensions:?}`. \
+                Loader must be specified in a .meta file in order to load assets of this type with these extensions.");
             }
 
             list.push(loader_index);
@@ -98,14 +101,15 @@ impl AssetLoaders {
 
         self.preregistered_loaders.insert(type_name, loader_index);
         self.type_name_to_loader.insert(type_name, loader_index);
+        let mut duplicate_extensions = Vec::new();
         for extension in extensions {
             let list = self
                 .extension_to_loaders
                 .entry(extension.to_string())
                 .or_default();
 
             if !list.is_empty() {
-                warn!("duplicate preregistration for extension `{extension}`.");
+                duplicate_extensions.push(extension);
             }
 
             list.push(loader_index);
@@ -116,8 +120,10 @@ impl AssetLoaders {
             .entry(loader_asset_type)
             .or_default();
 
-        if !list.is_empty() {
-            info!("duplicate preregistration for type `{loader_asset_type_name}`.");
+        let duplicate_asset_registration = !list.is_empty();
+        if !duplicate_extensions.is_empty() && duplicate_asset_registration {
+            warn!("Duplicate AssetLoader preregistered for Asset type `{loader_asset_type_name}` with extensions `{duplicate_extensions:?}`. \
+            Loader must be specified in a .meta file in order to load assets of this type with these extensions.");
         }
 
         list.push(loader_index);