fix: remove incorrect tooltip on remaining credit balance (#7383)

## Summary
Removed incorrect tooltip displayed on the remaining credit balance in
the subscription panel.

## Changes
- **What**: Removed unused `refreshTooltip` destructure and i18n
translation key
- **Breaking**: None

Fixes #6694

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7383-fix-remove-incorrect-tooltip-on-remaining-credit-balance-2c66d73d3650814eaee0f3c9006b7bd6)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Claude <noreply@anthropic.com>

src/platform/cloud/subscription/components/SubscriptionPanel.vue

@@ -138,19 +138,6 @@
                         >
                           {{ $t('subscription.creditsRemainingThisMonth') }}
                         </div>
-                        <Button
-                          v-tooltip="refreshTooltip"
-                          icon="pi pi-question-circle"
-                          text
-                          rounded
-                          size="small"
-                          class="h-4 w-4 shrink-0"
-                          :pt="{
-                            icon: {
-                              class: 'text-text-secondary text-xs'
-                            }
-                          }"
-                        />
                       </div>
                     </div>
                     <div class="flex items-center gap-4">
@@ -440,7 +427,6 @@ const { totalCredits, monthlyBonusCredits, prepaidCredits, isLoadingBalance } =
 
 const {
   isLoadingSupport,
-  refreshTooltip,
   handleAddApiCredits,
   handleMessageSupport,
   handleRefresh,