Sign is unnecessarily async

[paulmillr]

This includes all methods that call sign - there are many of them. They could be sync, because underlying primitive is sync.

This is breaking change.

https://github.com/wagmi-dev/viem/blob/d5eb4936438950714bef63c48b71d1d21358af60/src/accounts/utils/sign.ts#L20-L24

[jxom]

Will add a note to change this to sync for v2.

Background: it was originally async, and we didn’t want to break users (yet) so we left it async.

[paulmillr]

this hasn't been fixed in v2

[tmm]

Forgot to add a TODO comment for v2 😬 Coming in v3