[v6] Remove @rjsf/material-ui theme (Material UI v4) (rjsf-team#4010)

Author: nickgros

CHANGELOG.md

@@ -443,6 +443,10 @@ should change the heading of the (upcoming) version to include a major version b
 
 - BREAKING CHANGE: Removed `@rjsf/material-ui` package. Material UI v4 (`@material-ui/core`) has been deprecated since September 2021. To use Material UI v5 (`@mui/core`) with RJSF, please use the `@rjsf/mui` theme instead.
 
+## @rjsf/material-ui
+
+- Removed `@rjsf/material-ui` package. Material UI v4 (`@material-ui/core`) has been deprecated since September 2021. To use Material UI v5 (`@mui/core`) with RJSF, please use the `@rjsf/mui` theme instead.
+
 ## @rjsf/react-bootstrap
 
 - Added new package to replace `@rjsf/bootstrap-4`

packages/core/src/components/Form.tsx

@@ -1052,9 +1052,9 @@ export default class Form<
     const registry = this.getRegistry();
     const { SchemaField: _SchemaField } = registry.fields;
     const { SubmitButton } = registry.templates.ButtonTemplates;
-    // The `semantic-ui` and `material-ui` themes have `_internalFormWrapper`s that take an `as` prop that is the
+    // The `semantic-ui` theme has an `_internalFormWrapper` that take an `as` prop that is the
     // PropTypes.elementType to use for the inner tag, so we'll need to pass `tagName` along if it is provided.
-    // NOTE, the `as` prop is native to `semantic-ui` and is emulated in the `material-ui` theme
+    // NOTE, the `as` prop is native to `semantic-ui`
     const as = _internalFormWrapper ? tagName : undefined;
     const FormTag = _internalFormWrapper || tagName || 'form';