docs(migration): update version number to 8 for Ionic Vue steps (#3785)

Author: MichaelW-Dev

docs/updating/8-0.md

@@ -50,7 +50,7 @@ npm install @ionic/react@8 @ionic/react-router@8
 
 ### Vue
 
-1. Ionic 7 supports Vue 3.0.6+. Update to the latest version of Vue:
+1. Ionic 8 supports Vue 3.0.6+. Update to the latest version of Vue:
 
 ```shell
 npm install vue@^3.0.6 vue-router@^3.0.6