fix: unknown error code "error" when used with msw@0.49.3

[valendres]

This PR resolves https://github.com/valendres/playwright-msw/issues/54

Root cause: MSW was updated to use Emitter from strict-event-emitter in 0.49.3 which broke compatibility with playwright-msw.

Solution: Update playwright-msw to use the same Emitter.

Testing notes: This change has been successfully tested with the following MSW versions:

• 0.47.3
• 0.47.4
• 0.48.2
• 0.48.3
• 0.49.0
• 0.49.1
• 0.49.2
• 0.49.3
• 1.0.0