This argument has been used since 3839dd4.

Even when this function was first add in 74f3242 the errback
callback was only used for the IDB failures, not the fetch failures.
Fetch failure were left to propagate to the global error handlers.

This is small cleanup in advance of emscripten-core#24893.

This argument has been used since 3839dd4.

Even when this function was first add in 74f3242 the errback
callback was only used for the IDB failures, not the fetch failures.
Fetch failure were left to propagate to the global error handlers.

This is small cleanup in advance of emscripten-core#24893.

This argument has basically used since 3839dd4.

Even when this function was first add in 74f3242 the errback
callback was only used for the IDB failures, not the fetch failures.
Fetch failure were left to propagate to the global error handlers.

The exception here was that when node support was added in emscripten-core#11785 it,
I believe incorrectly used errback to handle file read errors (doesn't
match the web version that does *not* handle fetch error using errback).

This is small cleanup in advance of emscripten-core#24893.

This argument has been used since 3839dd4.

Even when this function was first added in 74f3242, `errback` was
only used for the IDB failures, not the fetch failures. Fetch failure
were left to propagate to the global error handlers.

The exception here was that when node support was added in #11785 it, I
believe incorrectly used errback to handle file read errors (doesn't
match the web version that does *not* handle fetch error using errback).

I'm not claiming this is correct/best behaviour, this is simply an NFC
to cleanup an already-unused argument.

This is small cleanup in advance of #24893.