typo: fix ThemeListModal component empty actions typo

Signed-off-by: Ryan Wang <i@ryanc.cc>

src/modules/interface/themes/components/ThemeListModal.vue

@@ -109,7 +109,7 @@ defineExpose({
             <template #icon>
               <IconAddCircle class="h-full w-full" />
             </template>
-            新增菜单项
+            安装主题
           </VButton>
         </VSpace>
       </template>

src/modules/interface/themes/layouts/ThemeLayout.vue

@@ -181,9 +181,7 @@ watch(
       >
         <template #actions>
           <VSpace>
-            <VButton @click="themesModal = true">
-              安装主题
-            </VButton>
+            <VButton @click="themesModal = true"> 安装主题 </VButton>
             <VButton type="primary" @click="themesModal = true">
               <template #icon>
                 <IconExchange class="h-full w-full" />