Undici MockAgent cannot intercept fetch request anymore

[Guymestef]

Hello,
You made a PR on vitest to use fetch() implementation from happy-dom: vitest-dev/vitest#6879
With this change we cannot mock anymore the http calls with the MockAgent of undici.
Issue created on vitest: vitest-dev/vitest#6952

Can you have a look to have undici mock working with happy-dom fetch?

Thank you