chore: remove note about v3 (#9090)

README.md

@@ -33,17 +33,6 @@ In addition, Vite is highly extensible via its [Plugin API](https://vitejs.dev/g
 
 [Read the Docs to Learn More](https://vitejs.dev).
 
-## v3.0
-
-Current Status: **Beta** (for internal testing, not recommended for production)
-
-The `main` branch is now for v3.0, if you are looking for current stable releases, check the [`v2` branch](https://github.com/vitejs/vite/tree/v2) branch instead.
-
-We will start drafting release notes and migration guide for v3.0 when we enter the beta stage. Before that you can check:
-
-- [v3.0 Milestone](https://github.com/vitejs/vite/milestone/5)
-- [Breaking Change List](https://github.com/vitejs/vite/issues?q=label%3A%22breaking+change%22+is%3Aclosed+milestone%3A3.0)
-
 ## Packages
 
 | Package                                           | Version (click for changelogs)                                                                                                       |