fix(TextArea): add aria-live and aria-placeholder (#6819)

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

packages/react/src/components/TextArea/TextArea.js

@@ -25,6 +25,7 @@ const TextArea = React.forwardRef(function TextArea(
     invalidText,
     helperText,
     light,
+    placeholder,
     ...other
   },
   ref
@@ -66,7 +67,7 @@ const TextArea = React.forwardRef(function TextArea(
   const errorId = id + '-error-msg';
 
   const error = invalid ? (
-    <div className={`${prefix}--form-requirement`} id={errorId}>
+    <div role="alert" className={`${prefix}--form-requirement`} id={errorId}>
       {invalidText}
     </div>
   ) : null;
@@ -80,6 +81,8 @@ const TextArea = React.forwardRef(function TextArea(
     <textarea
       {...other}
       {...textareaProps}
+      placeholder={placeholder}
+      aria-placeholder={placeholder} // for JAWS support
       className={textareaClasses}
       aria-invalid={invalid || null}
       aria-describedby={invalid ? errorId : null}