`theme` attribute does not update dynamically

[sissbruecker]

The theme attribute on Vaadin React components (e.g., Button, TextField, ComboBox) does not update dynamically when the theme prop is changed after the initial render.

Steps to Reproduce:

• Render a Vaadin React component (e.g., Button) with a theme prop bound to a state variable.
• Update the state variable that controls the theme prop.
• Observe that the component's visual theme does not change, the attribute does not update.

Example:

export default function Repro() {
  const [theme, setTheme] = useState('');
  return (
    <>
      <Button theme={theme}>Foo</Button>
      <TextField theme={theme} />
      <ComboBox theme={theme}></ComboBox>
      <input type="checkbox" onChange={(e) => setTheme(e.target.checked ? 'small' : '')} />
    </>
  );
}