[eslint-plugin-mobx] fix test after upstream type name change (DefinitelyTyped#73960)

Author: jakebailey

types/eslint-plugin-mobx/eslint-plugin-mobx-tests.ts

@@ -1,3 +1,3 @@
 import pluginMobx = require("eslint-plugin-mobx");
-pluginMobx.configs.recommended; // $ExpectType Config<RulesRecord>
-pluginMobx.flatConfigs.recommended; // $ExpectType Config<RulesRecord>
+pluginMobx.configs.recommended; // $ExpectType Config<RulesRecord> || Config<RulesConfig>
+pluginMobx.flatConfigs.recommended; // $ExpectType Config<RulesRecord> || Config<RulesConfig>