Matt Harbison <matt_harbison@yahoo.com> [Fri, 24 Mar 2023 02:22:12 -0400] rev 50329
typing: correct the signature of error.CommandError
There's a place in `mercurial.dispatch._parse()` that passes None if a parse
error happens before the command can be parsed out, and casting the error to
bytes works fine because the command and message fields are apparently ignored.
Likewise, TortoiseHg similarly passes None for the same reason.