Remove dependency on xerrors

[nhooyr]

Remove dependency on xerrors

[nhooyr]

This means we would lose stack frames for now, which is fine I think given most of our error wraps are easily identifiable via text.

Thoughts @ammario @scsmithr @nathanpotter @coadler

[coadler]

I disagree. I find the stack frames extremely helpful, especially in slog.Human.

What do we gain from removing xerrors?

[scsmithr]

I agree with Colin.

[nhooyr]

Sounds good.

Less external dependencies, it's nice to be able to only depend on the stdlib.

[coadler]

Really unfortunate it was merged into the stdlib without traces :/

[nhooyr]

Agreed