Rename ChunkLoading::None to ChunkLoading::Edge (#8376)

### Description

Changing the name in order to reflect reality after talking to @sokra.

<!--
  ✍️ Write a short summary of your work.
  If necessary, include relevant screenshots.
-->

### Testing Instructions

<!--
  Give a quick description of steps to test your changes.
-->

crates/turbopack-core/src/chunk/mod.rs

@@ -420,7 +420,7 @@ async fn graph_node_to_referenced_nodes(
                         ChunkingType::Async => {
                             let chunk_loading =
                                 chunking_context.environment().chunk_loading().await?;
-                            if matches!(*chunk_loading, ChunkLoading::None) {
+                            if matches!(*chunk_loading, ChunkLoading::Edge) {
                                 let chunk_item = chunkable_module
                                     .as_chunk_item(chunking_context)
                                     .resolve()

crates/turbopack-core/src/environment.rs

@@ -28,10 +28,8 @@ impl Rendering {
 }
 
 #[turbo_tasks::value]
-#[derive(Default)]
 pub enum ChunkLoading {
-    #[default]
-    None,
+    Edge,
     /// CommonJS in Node.js
     NodeJs,
     /// <script> and <link> tags in the browser
@@ -221,9 +219,9 @@ impl Environment {
             ExecutionEnvironment::NodeJsBuildTime(_) | ExecutionEnvironment::NodeJsLambda(_) => {
                 ChunkLoading::NodeJs.cell()
             }
-            ExecutionEnvironment::EdgeWorker(_) => ChunkLoading::None.cell(),
+            ExecutionEnvironment::EdgeWorker(_) => ChunkLoading::Edge.cell(),
             ExecutionEnvironment::Browser(_) => ChunkLoading::Dom.cell(),
-            _ => ChunkLoading::None.cell(),
+            ExecutionEnvironment::Custom(_) => todo!(),
         })
     }
 }

crates/turbopack-ecmascript-runtime/src/dev_runtime.rs

@@ -35,7 +35,7 @@ pub async fn get_browser_runtime_code(
     let runtime_backend_code = embed_static_code(
         asset_context,
         match chunk_loading {
-            ChunkLoading::None => "dev/runtime/none/runtime-backend-none.ts".into(),
+            ChunkLoading::Edge => "dev/runtime/none/runtime-backend-none.ts".into(),
             ChunkLoading::NodeJs => "dev/runtime/nodejs/runtime-backend-nodejs.ts".into(),
             ChunkLoading::Dom => "dev/runtime/dom/runtime-backend-dom.ts".into(),
         },

crates/turbopack-ecmascript/src/references/esm/dynamic.rs

@@ -107,7 +107,7 @@ impl CodeGenerateable for EsmAsyncAssetReference {
             ),
             if matches!(
                 *chunking_context.environment().chunk_loading().await?,
-                ChunkLoading::None
+                ChunkLoading::Edge
             ) {
                 Value::new(ResolveType::ChunkItem)
             } else {