`ModalDecisionTrees` 0.5.4 is on main but 0.5.3 is the newest registered version

`Project.toml` on the default branch declares:

```toml
version = "0.5.4"
```

The Julia General registry's newest entry for `ModalDecisionTrees` is **0.5.3**.

So anyone installing through `Pkg` gets 0.5.3, and whatever changed to justify the bump to 0.5.4 is not
reachable that way. The gap is invisible from a git checkout, which is how it tends to persist.

For context, this is not an ecosystem-wide lag: `SoleLogics` (0.13.7), `SoleModels` (0.10.8) and
`ModalDecisionLists` (0.1.0) are each in sync between main and the registry. Three packages have
stalled - this one, and two reported separately in their own repositories.

### What would close it

Tagging the release so the registrator picks it up, or - if the bump was provisional and not meant to
ship yet - nothing at all, in which case this issue can close with that as the answer. Either is
useful to know from outside.

Noticed during an outside survey of the ecosystem.