fix: ignore incoming transactions in duplicate nonce check (#7097)

## Explanation

Ignore transactions with `isTransfer` set when checking for duplicate
nonces in `PendingTransactionTracker`.

## References

Related to
[#6135](MetaMask/MetaMask-planning#6135)

## Checklist

- [x] I've updated the test suite for new or updated code as appropriate
- [x] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [x] I've communicated my changes to consumers by [updating changelogs
for packages I've
changed](https://github.com/MetaMask/core/tree/main/docs/contributing.md#updating-changelogs),
highlighting breaking changes as necessary
- [x] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Prevents pending transactions from being marked dropped when their
nonce matches an incoming/transfer transaction by refining the
nonce-taken check.
> 
> - **PendingTransactionTracker**:
> - Refine `#isNonceTaken` to exclude transactions where `tx.type !==
incoming` AND `tx.isTransfer !== undefined`, avoiding false
duplicate-nonce drops from incoming/transfer transactions.
> - Add unit test ensuring no `transaction-dropped` event when a
matching nonce belongs to an incoming transaction.
> - **Changelog**:
> - Document fix: prevent transactions marked as `dropped` if nonce
matches incoming transaction.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
77e52f5. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: matthewwalsh0

packages/transaction-controller/CHANGELOG.md

@@ -12,6 +12,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Calculate operator fee for OP stack networks and include it in `layer1GasFee` ([#6979](https://github.com/MetaMask/core/pull/6979))
 - Add support for `isGasFeeSponsored` field in transaction batch and add transaction options ([#7064](https://github.com/MetaMask/core/pull/7064))
 
+### Fixed
+
+- Prevent transactions marked as `dropped` if nonce matches incoming transaction ([#7097](https://github.com/MetaMask/core/pull/7097))
+
 ## [61.1.0]
 
 ### Added

packages/transaction-controller/src/helpers/PendingTransactionTracker.test.ts

@@ -565,6 +565,38 @@ describe('PendingTransactionTracker', () => {
 
           expect(listener).not.toHaveBeenCalled();
         });
+
+        it('unless incoming transaction', async () => {
+          const listener = jest.fn();
+
+          const confirmedTransactionMetaMock = {
+            ...TRANSACTION_SUBMITTED_MOCK,
+            id: `${ID_MOCK}2`,
+            status: TransactionStatus.confirmed,
+            isTransfer: false,
+          } as unknown as TransactionMeta;
+
+          const submittedTransactionMetaMock = {
+            ...TRANSACTION_SUBMITTED_MOCK,
+          };
+
+          pendingTransactionTracker = new PendingTransactionTracker({
+            ...options,
+            getTransactions: () => [
+              confirmedTransactionMetaMock,
+              submittedTransactionMetaMock,
+            ],
+          });
+
+          pendingTransactionTracker.hub.addListener(
+            'transaction-dropped',
+            listener,
+          );
+
+          await onPoll();
+
+          expect(listener).not.toHaveBeenCalled();
+        });
       });
 
       describe('fires confirmed event', () => {

packages/transaction-controller/src/helpers/PendingTransactionTracker.ts

@@ -543,7 +543,8 @@ export class PendingTransactionTracker {
         tx.status === TransactionStatus.confirmed &&
         tx.txParams.nonce &&
         tx.txParams.nonce === txParams.nonce &&
-        tx.type !== TransactionType.incoming,
+        tx.type !== TransactionType.incoming &&
+        tx.isTransfer === undefined,
     );
   }