Replace the use of pkg/errors with native error wrapping

[yurishkuro]

currently we're using errors.Wrap. Since Go 1.13 we can instead use the stdlib

if err != nil {
    return fmt.Errorf("bad thing happend: %w", err)
}

[u5surf]

@yurishkuro
I'll give you a resolve this issue, I experienced the making a resolution of same error-wrapping issue (tektoncd/pipeline#808) using xerrors.
Of course, I know we can wrap with current fmt libraries as you referred.