chore: Cleanup manager decorator usage (#9181)

packages/core/utils/src/modules-sdk/decorators/inject-manager.ts

@@ -13,6 +13,8 @@ export function InjectManager(managerProperty?: string): MethodDecorator {
       )
     }
 
+    managerProperty ??= "baseRepository_"
+
     const originalMethod = descriptor.value
     const argIndex = target.MedusaContextIndex_[propertyKey]