fix: Mutex never gets released on refresh function of AccountTrackerC…

…ontroller (#4270)

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Currently the mutex do not get released unless there is an error thrown
by the `getBalanceFromChain` function
Fixed by move the release of the murex to the finally block. It was also
removed unnecessary catch block.

Now the mutex gets released when the logic of refresh runs successfully 

### Fixed
- Ensure mutex is released when refresh succeeds
- Previously the `refresh` method would remain locked indefinitely after
it was run successfully. The mutex was only released upon failure.

## References

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## Changelog

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### `@metamask/assets-controllers`

- **FIXED**: Mutex released on the finally block of refresh function


## Checklist

- [ ] I've updated the test suite for new or updated code as appropriate
- [ ] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [ ] I've highlighted breaking changes using the "BREAKING" category
above as appropriate

packages/assets-controllers/src/AccountTrackerController.ts

@@ -285,9 +285,8 @@ export class AccountTrackerController extends StaticIntervalPollingControllerV1<
           [chainId]: accountsForChain,
         },
       });
-    } catch (err) {
+    } finally {
       releaseLock();
-      throw err;
     }
   };