fix(Carousel/Tree): add type to button elements for accessibility (#4493)

Author: hywax

src/runtime/components/Carousel.vue

@@ -336,6 +336,7 @@ defineExpose({
       <div v-if="dots" :class="ui.dots({ class: props.ui?.dots })">
         <template v-for="(_, index) in scrollSnaps" :key="index">
           <button
+            type="button"
             :aria-label="t('carousel.goto', { slide: index + 1 })"
             :class="ui.dot({ class: props.ui?.dot, active: selectedIndex === index })"
             :data-state="selectedIndex === index ? 'active' : undefined"

src/runtime/components/Tree.vue

@@ -163,7 +163,7 @@ const defaultExpanded = computed(() =>
         @toggle="item.onToggle"
         @select="item.onSelect"
       >
-        <button :disabled="item.disabled || disabled" :class="ui.link({ class: [props.ui?.link, item.ui?.link, item.class], selected: isSelected, disabled: item.disabled || disabled })">
+        <button type="button" :disabled="item.disabled || disabled" :class="ui.link({ class: [props.ui?.link, item.ui?.link, item.class], selected: isSelected, disabled: item.disabled || disabled })">
           <slot :name="((item.slot || 'item') as keyof TreeSlots<T>)" v-bind="{ index, level, expanded: isExpanded, selected: isSelected }" :item="(item as Extract<NestedItem<T>, { slot: string; }>)">
             <slot :name="((item.slot ? `${item.slot}-leading`: 'item-leading') as keyof TreeSlots<T>)" v-bind="{ index, level, expanded: isExpanded, selected: isSelected }" :item="(item as Extract<NestedItem<T>, { slot: string; }>)">
               <UIcon