mui: fix gap in outline when label is hidden

Passing `label={false}` to the MUI text/select widgets results in a
gap in the widget outline where the label would be.  Instead, to hide
the label without a gap, we must pass `label={undefined}`.

This commit changes the calls to `labelValue(...)` for
BaseInputTemplatea and SelectWidget to return `undefined` when
`"ui:label": false` was specified.

CHANGELOG.md

@@ -15,6 +15,12 @@ it according to semantic versioning. For example, if your PR adds a breaking cha
 should change the heading of the (upcoming) version to include a major version bump.
 
 -->
+# 5.14.5
+
+## @rjsf/mui
+
+- fix gap in text and select widget outlines when `"ui:label": false` is specified.
+
 # 5.14.4
 
 ## @rjsf/utils

packages/mui/src/BaseInputTemplate/BaseInputTemplate.tsx

@@ -79,7 +79,7 @@ export default function BaseInputTemplate<
         id={id}
         name={id}
         placeholder={placeholder}
-        label={labelValue(label || undefined, hideLabel, false)}
+        label={labelValue(label || undefined, hideLabel, undefined)}
         autoFocus={autofocus}
         required={required}
         disabled={disabled || readonly}

packages/mui/src/SelectWidget/SelectWidget.tsx

@@ -64,7 +64,7 @@ export default function SelectWidget<
     <TextField
       id={id}
       name={id}
-      label={labelValue(label || undefined, hideLabel, false)}
+      label={labelValue(label || undefined, hideLabel, undefined)}
       value={!isEmpty && typeof selectedIndexes !== 'undefined' ? selectedIndexes : emptyValue}
       required={required}
       disabled={disabled || readonly}