[instrumentation-fetch] Response with null body status cannot have body errors

[m0sa]

What happened?

instrumentation-fetch is throwing a "Response with null body status cannot have body" TypeError when the instrumented request returns a null-body-status response (status codes 101, 204, 205, or 304)

Steps to Reproduce

I've created a tests to reproduce it here: m0sa@ecb5557

That test passes in v0.205.0, but fails in v0.206.0 and v0.207.0.