Fix rjsf-team#3228, rjsf-team#3213

Playground
- Playground `localValidator` should use @rjsf/validator-ajv8
- Upgrade Vite and @vitejs/plugin-react to latest

@rjsf/validator-ajv8
- Alias `ajv` to `ajv8` because in the playground, Vite erroneously imports Ajv 6
- Report any schema error thrown by Ajv
- Disable Ajv's strict mode by default
- Add RJSF-specific additional properties keywords to Ajv to prevent errors from being reported in strict mode.
-

CHANGELOG.md

@@ -20,6 +20,12 @@ should change the heading of the (upcoming) version to include a major version b
 ## @rjsf/playground
 - Fix Vite development server [#3228](https://github.com/rjsf-team/react-jsonschema-form/issues/3228)
 
+## @rjsf/validator-ajv8
+- Fix additionalProperties validation [#3213](https://github.com/rjsf-team/react-jsonschema-form/issues/3213)
+- Report all schema errors thrown by Ajv. Previously, we would only report errors thrown for a missing meta-schema. This behavior is unchanged for @rjsf/validator-ajv6.
+- Disable Ajv strict mode by default.
+- Add RJSF-specific additional properties keywords to Ajv to prevent errors from being reported in strict mode.
+
 # 5.0.0-beta.12
 
 ## @rjsf/antd