docs(iconbutton): Remove deprecated `icon-size` mixin: https://github.com/material-components/material-components-web/blob/43c1c5e2fc3b679ffa5ff60c0b624b2c812482ac/packages/mdc-icon-button/_mixins.scss#L132
docs(iconbutton): Remove deprecated `icon-size` mixin: https://github.com/material-components/material-components-web/blob/43c1c5e2fc3b679ffa5ff60c0b624b2c812482ac/packages/mdc-icon-button/_mixins.scss#L132

PiperOrigin-RevId: 338075339

material-components/material-components-web,material-components/material-components-web,material-components/material-components-web