fix(radio-button): add missing slot optioin (#11307)

### Related Ticket(s)

Closes #11288 
### Description

fixes slot for radio-button
### Changelog

**New**

- {{new thing}}

**Changed**

- accidentally got removed .... but adding `<slot>` around `${labelText}`

**Removed**

- {{removed thing}}

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packages/carbon-web-components/src/components/radio-button/radio-button.ts

@@ -371,7 +371,7 @@ class CDSRadioButton extends HostListenerMixin(FocusMixin(LitElement)) {
       <label for="input" class="${prefix}--radio-button__label">
         <span class="${prefix}--radio-button__appearance"></span>
         <span class="${innerLabelClasses}"
-          >${labelText}
+          ><slot>${labelText}</slot>
           <slot name="slug" @slotchange="${this._handleSlotChange}"></slot
         ></span>
       </label>