remove unused updating reference

Author: mallardduck

README.md

@@ -29,10 +29,6 @@ If you currently live in Russia, please read [this message](./ToRussianPeople.md
 composer require mallardduck/blade-lucide-icons
 ```
 
-## Updating
-
-Please refer to [`the upgrade guide`](UPGRADE.md) when updating the library.
-
 ## Blade Icons
 
 Blade LucideIcons uses Blade Icons under the hood. Please refer to [the Blade Icons readme](https://github.com/blade-ui-kit/blade-icons) for additional functionality. We also recommend to [enable icon caching](https://github.com/blade-ui-kit/blade-icons#caching) with this library.