Since we're no longer using storage keys to refer to elements and
regulators, we don't need to store these items in keyed collections
anymore.
To keep element and regulator pointers in `BTreeSet` collections, we
implement `Ord` for `Serial` trait objects. As a bonus, this lets us
turn the element-wise regulator collections back into `BTreeSet`.
Adds a continuous integration workflow to the repository, using the [Forgejo Actions](https://forgejo.org/docs/next/user/actions/) framework.
Concurrently, Aaron added a [wiki page](https://code.studioinfinity.org/glen/dyna3/wiki/Continuous-integration) to document the continuous integration system. In particular, this page explains how to [run continuous integration checks on a development machine](wiki/Continuous-integration#execution), either directly or in a container.
Co-authored-by: Aaron Fenyes <aaron.fenyes@fareycircles.ooo>
Co-authored-by: Glen Whitney <glen@studioinfinity.org>
Reviewed-on: StudioInfinity/dyna3#75
Co-authored-by: Vectornaut <vectornaut@nobody@nowhere.net>
Co-committed-by: Vectornaut <vectornaut@nobody@nowhere.net>