Remove code apparently obsoleted due to defaultness of pretty

[swaldman]

I apologize for the very trivial pull request!

While beginning to learn / find my way around the codebase, I found a couple of methods of PathSpec that seem to be obsolete, replaced by more newer functionality. Maybe they should be removed?

[CLAassistant]

All committers have signed the CLA.

[swaldman]

Looking around at code involving pretty vs ugly URLs, it looks like a bunch of code is no longer used since pretty-style URLs are now default.

[github-actions]

This PR has been automatically marked as stale because it has not had recent activity. The resources of the Hugo team are limited, and so we are asking for your help.
Please check https://github.com/gohugoio/hugo/blob/master/CONTRIBUTING.md#code-contribution and verify that this code contribution fits with the description. If yes, tell is in a comment.
This PR will automatically be closed in the near future if no further activity occurs. Thank you for all your contributions.

[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.