fix(v-select): change isDisabled conditional
fix(v-select): change isDisabled conditional

should use regular text color when readonly

fixes #5051

Webifi/vuetify,vuetifyjs/vuetify,vuetifyjs/vuetify,Phlow2001/vuetify,Phlow2001/vuetify,Phlow2001/vuetify,vuetifyjs/vuetify,Phlow2001/vuetify,Webifi/vuetify,Webifi/vuetify,vuetifyjs/vuetify