build(deps): bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

ci: woodpecker uses a different env to indicate tagging

cargo update

update trust-dns-resolver to 0.23

With the mail-auth dep removed, we can now update this dep.

build-deb: include version number in filename

I suspect that using the same name on upload to openrepo
somehow collides with other versions that use the same uploaded
filename.

refs: openkilt/openrepo#11

add selene linter config

This is relatively basic in that it can catch general lua lints,
but doesn't know about the set of functions available to kumo.

It doesn't appear as though selene is able to be extended to
know about those yet; that is tracked by
Kampfkarren/selene#520

I've fixed the couple of lints in our policy and test files
as part of this commit.

You can install and run it like this:

```console
$ cargo install selene
```

Then:

```console
$ selene .
```

Update changelog.

docs: show repo name in GH link in top right corner

ci: maybe publish the right bits to the right place on tag

Aligning chapter names.