fix: Add back ExtensionRunnerConfig as deprecated (#1311)

Author: aklinker1

packages/wxt/src/types.ts

@@ -906,6 +906,11 @@ export interface ConfigEnv {
 
 export type WxtCommand = 'build' | 'serve';
 
+/**
+ * @deprecated Use `WebExtConfig` instead.
+ */
+export type ExtensionRunnerConfig = WebExtConfig;
+
 /**
  * Options for how [`web-ext`](https://github.com/mozilla/web-ext) starts the browser.
  */