fix: set upgrade-to/v7.mdx as i18n ready (#14207)

Co-authored-by: delucis <357379+delucis@users.noreply.github.com>

Author: ArmandPhilippot

src/content/docs/en/guides/upgrade-to/v7.mdx

@@ -3,7 +3,7 @@ title: Upgrade to Astro v7
 description: How to upgrade your project to Astro v7.0.
 sidebar:
   label: v7.0
-i18nReady: false
+i18nReady: true
 ---
 import PackageManagerTabs from '~/components/tabs/PackageManagerTabs.astro'
 import { Steps } from '@astrojs/starlight/components';