Fix Jest worker process cleanup in design-system-react-native tests

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### **Description**

The Jest tests in the `@metamask/design-system-react-native` package are experiencing worker process cleanup issues, specifically with the `react-native-jazzicon` component in the `AvatarAccount` tests. This is causing tests to fail with the error "A worker process has failed to exit gracefully and has been force exited."

Additionally, the `react-native-jazzicon` package is using the deprecated React lifecycle method `componentWillReceiveProps`, which is contributing to the cleanup issues.

### **Technical Details**

- The issue stems from improper cleanup of the `react-native-jazzicon` component after tests
- The `AvatarAccount` component tests are not properly cleaning up resources after each test case
- Upstream issue: `react-native-jazzicon` package uses deprecated `componentWillReceiveProps` lifecycle method
- Related issue filed in `react-native-jazzicon` repository: https://github.com/stanislaw-glogowski/react-native-jazzicon/issues/3

### **Acceptance Criteria**

- [ ] Implement proper cleanup in `jest.setup.js` for the `react-native-jazzicon` mock
- [ ] Add cleanup after each test in `AvatarAccount.test.tsx`
- [ ] Ensure tests pass without worker process errors
- [ ] Maintain existing test coverage and functionality
- [ ] Verify cleanup works across all test cases
- [ ] Monitor upstream `react-native-jazzicon` issue for updates regarding the deprecated lifecycle method

### **References**

- Related to test cleanup issues in React Native Testing Library
- Affects the `AvatarAccount` component tests
- Current error: "A worker process has failed to exit gracefully and has been force exited"
- Solution involves proper mocking and cleanup of the `react-native-jazzicon` component
- Upstream issue: https://github.com/stanislaw-glogowski/react-native-jazzicon/issues/3

Start with jest.setup.js and AvatarAccount.test.tsx, then run the affected Jest tests to reproduce the worker process cleanup error. Implement the specified mock and per-test cleanup, and verify that all AvatarAccount tests pass without worker-process errors while preserving existing coverage and functionality.

Written by the indexing model from the issue text.