fix upgrade model style

Signed-off-by: andy.lee <andy.lee@suse.com>

pkg/harvester/components/HarvesterUpgradeHeader.vue

@@ -190,6 +190,7 @@ export default {
       v-clean-tooltip="{
         placement: 'bottom-left',
       }"
+      popper-class="upgrade-header-dropdown"
       class="hand"
     >
       <slot name="button-content">
@@ -338,6 +339,12 @@ export default {
   </div>
 </template>
 
+<style lang="scss">
+.upgrade-header-dropdown .v-popper__arrow-container {
+  display: none;
+}
+</style>
+
 <style lang="scss" scoped>
 a {
   float: right;