fix: blocking button even when there's an active quote (MetaMask#23792)

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## **Description**

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This PR fixes an issue that caused Swap button to be blocked even though
a quote was available.

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CHANGELOG entry: Fixed a bug that caused Swap button to be blocked even
though a quote was available

## **Related issues**

Fixes: https://consensyssoftware.atlassian.net/browse/SWAPS-3559

## **Manual testing steps**

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Feature: my feature name

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https://github.com/user-attachments/assets/4e38deb6-61d9-4b39-aaa0-ecf31906b5af



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<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Adjusts `isSubmitDisabled` so the confirm button remains enabled
during loading when an `activeQuote` exists.
> 
> - **Bridge UI
(`app/components/UI/Bridge/Views/BridgeView/index.tsx`)**:
> - Refines `isSubmitDisabled` to `(isLoading && !activeQuote)` instead
of `isLoading`, allowing confirm when a quote is already available.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
5754e63. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: infiniteflower

app/components/UI/Bridge/Views/BridgeView/index.tsx

@@ -228,7 +228,7 @@ const BridgeView = () => {
   ]);
 
   const isSubmitDisabled =
-    isLoading ||
+    (isLoading && !activeQuote) ||
     hasInsufficientBalance ||
     isSubmittingTx ||
     (isHardwareAddress && isSolanaSourced) ||