Use self-closing slot tags everywhere (#7717)

app/src/components/v-badge/v-badge.vue

@@ -5,7 +5,7 @@
 			<span v-else>{{ value }}</span>
 		</span>
 
-		<slot></slot>
+		<slot />
 	</div>
 </template>
 

app/src/components/v-list/v-list-item-content.vue

@@ -1,6 +1,6 @@
 <template>
 	<div class="v-list-item-content">
-		<slot></slot>
+		<slot />
 	</div>
 </template>
 

app/src/components/v-list/v-list-item-icon.vue

@@ -1,6 +1,6 @@
 <template>
 	<div class="v-list-item-icon" :class="{ center }">
-		<slot></slot>
+		<slot />
 	</div>
 </template>
 

app/src/components/v-progress/circular/v-progress-circular.vue

@@ -18,7 +18,7 @@
 				transform="translate(2.5 2.5)"
 			/>
 		</svg>
-		<slot></slot>
+		<slot />
 	</div>
 </template>