Remove the PluginWebpackEnvInfo alias

Only core uses the type, so there is no need to keep the old name
around (Cooldude in #1130).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/devs/plugin-migration-to-2.1.md

@@ -59,4 +59,3 @@ Imports of `assert`, `buffer`, `events`, `os`, `path`, `process`, `stream`, `uti
 The `container` property of `WebPluginContext` is now the plugin's ES module namespace, `await container.get("./web")` returns the module instead of a factory function.
 
 `lib.PluginWebpackEnvInfo` is renamed to `lib.PluginWebEnvInfo`.
-The old name still works but is deprecated and will be removed.

packages/lib/src/plugin.ts

@@ -98,9 +98,6 @@ export type PluginWebEnvInfo = PluginDeclaration & {
 	error?: string;
 };
 
-/** @deprecated Use PluginWebEnvInfo */
-export type PluginWebpackEnvInfo = PluginWebEnvInfo;
-
 /**
  * Information about the event.
  */