fix: don’t force open ImagePickerDialog

Using :is-open="true" interferes with the dialogs close function in
nested dialogs.

src/components/images/ImagePicker.vue

@@ -25,12 +25,7 @@
       </button>
     </div>
   </ImagePreview>
-  <ImagePickerDialog
-    v-if="showPicker"
-    v-model="localImageId"
-    :is-open="true"
-    @show="showPicker = $event"
-  />
+  <ImagePickerDialog v-model="localImageId" :is-open="showPicker" @show="showPicker = $event" />
 </template>
 
 <script lang="ts" setup>