feat: implement removeServerHot future deprecation (vitejs#20434)

Author: sapphi-red

docs/changes/per-environment-apis.md

@@ -15,6 +15,7 @@ The `Environment` instance was first introduced at `v6.0`. The deprecation of `s
 future: {
   removeServerModuleGraph: 'warn',
   removeServerPluginContainer: 'warn',
+  removeServerHot: 'warn',
   removeServerTransformRequest: 'warn',
   removeServerWarmupRequest: 'warn',
 }
@@ -34,3 +35,4 @@ In Vite v6, it is now possible to create any number of custom environments (`cli
 - `server.pluginContainer` -> `environment.pluginContainer`
 - `server.transformRequest(url, ssr)` -> `environment.transformRequest(url)`
 - `server.warmupRequest(url, ssr)` -> `environment.warmupRequest(url)`
+- `server.hot` -> `server.client.environment.hot`

packages/vite/src/node/server/index.ts

@@ -562,13 +562,20 @@ export async function _createServer(
     server._ssrCompatModuleRunner = undefined
   }
 
+  let hot = ws
   let server: ViteDevServer = {
     config,
     middlewares,
     httpServer,
     watcher,
     ws,
-    hot: ws,
+    get hot() {
+      warnFutureDeprecation(config, 'removeServerHot')
+      return hot
+    },
+    set hot(h) {
+      hot = h
+    },
 
     environments,
     get pluginContainer() {