Remove usage of github.com/pkg/errors which is now archived and deprecated

[kbutz]

The error handling package https://github.com/pkg/errors was archived on Nov 30, 2021 with preference for using the standard library for error handling.

As of go 1.13, wrapping errors is performed by using the fmt library and the %w formatting verb.

I checked open PRs and saw one that is now far behind main and has conflicts, but this branch could be updated if the original author still wants: #238

This is primarily a code cleanup task, no real behavior changes. I can open some new PRs when I have time, but wanted to track the issue first.