One new feature

• Passing the errorSchema to the ObjectFieldTemplate

@rjsf/antd

• Updated tests to use centralized snapshots from core

@rjsf/bootstrap-4

• Updated tests to use centralized snapshots from core

@rjsf/chakra-ui

• Updated tests to use centralized snapshots from core

@rjsf/core

• Updated FileWidget to pass false for required once a value has been specified, fixing #3504
• Updated ObjectField to pass the errorSchema to the ObjectFieldTemplate to allow custom templates access to the errors
• Centralized snapshot tests from each theme into core, adding snapshots tests for core as well

@rjsf/fluent-ui

• Updated tests to use centralized snapshots from core

@rjsf/material-ui

• Updated tests to use centralized snapshots from core

@rjsf/mui

• Updated tests to use centralized snapshots from core

@rjsf/semantic-ui

• Updated tests to use centralized snapshots from core

@rjsf/utils

• Added errorSchema as an optional prop on ObjectFieldTemplateProps

Dev / docs / playground

• Converted the playground to use Typescript, including some refactoring of code to make that job easier
• Updated the custom-templates documentation to add errorSchema to the props for ObjectFieldTemplate