Fetch bug

[guybedford]

I tried enabling the fetch path in the smoke test component here - https://github.com/fermyon/StarlingMonkey/blob/main/tests/smoke.js#L135.

But on the await textP line I get the following error:

stdout [1] :: Log: Error: TypeError: Response body object should not be disturbed or locked.

This is currently blocking enabling fetch on ComponentizeJS (https://github.com/bytecodealliance/ComponentizeJS/issues/96).