Don't abuse libtool internals

[jsonn]

The whole internals of .libs are an implementation detail of libtool. I'm leaving the whole to_copy mess for now as it doesn't actually break something for pkgsrc, but the dependency certainly does.

[alerque]

Thanks for these contributions @jsonn.

[simoncozens]

Thanks @jsonn!

@alerque, for future reference, what's the best way to edit contributed commits to conform to .commitlint rules? Check out manually and rebase -i?

[alerque]

@simoncozens For PRs like this one with a single commit using the "Squash and Merge" option allows you to write your own commit message. The downside of that is that you skip CI checks for the re-written commit message, but that's what I did here. For longer ones where you want to preserve the commit the history, yes a chekcout and rebase is necessary. To speed things up I use gh to make it easy to fetch and checkout a PR like this in such a way that you can also push back to it (gh pr checkout 1084), and also use git revise -i instead of rebase for faster iterating (it doesn't require stepping through each commit as the working copy, it basically just revises the commits directly).