chore: remove no longer present V_FOR_REF compat entry

close vuejs/v3-migration-guide#10

Author: yyx990803

packages/vue-compat/README.md

@@ -308,7 +308,6 @@ Features that start with `COMPILER_` are compiler-specific: if you are using the
 | OPTIONS_BEFORE_DESTROY       | ✔    | `beforeDestroy` -> `beforeUnmount`                                    |                                                                                            |
 | OPTIONS_DESTROYED            | ✔    | `destroyed` -> `unmounted`                                            |                                                                                            |
 | WATCH_ARRAY                  | ✔    | watching an array no longer triggers on mutation unless deep          | [link](https://v3-migration.vuejs.org/breaking-changes/watch.html)                                                        |
-| V_FOR_REF                    | ✔    | `ref` inside `v-for` no longer registers array of refs                | [link](https://v3-migration.vuejs.org/breaking-changes/array-refs.html)                                                   |
 | V_ON_KEYCODE_MODIFIER        | ✔    | `v-on` no longer supports keyCode modifiers                           | [link](https://v3-migration.vuejs.org/breaking-changes/keycode-modifiers.html)                                            |
 | CUSTOM_DIR                   | ✔    | Custom directive hook names changed                                   | [link](https://v3-migration.vuejs.org/breaking-changes/custom-directives.html)                                            |
 | ATTR_FALSE_VALUE             | ✔    | No longer removes attribute if binding value is boolean `false`       | [link](https://v3-migration.vuejs.org/breaking-changes/attribute-coercion.html)                                           |