Bump Fronter.NET from 5c996a1 to af6846f (#2183)

Bumps
[Fronter.NET](https://github.com/ParadoxGameConverters/Fronter.NET) from
`5c996a1` to `af6846f`.
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/ParadoxGameConverters/Fronter.NET/commit/af6846f1ac45c399a3881b168304ec7ca4ef1fe0"><code>af6846f</code></a>
Add <code>self_contained</code> input (<a
href="https://redirect.github.com/ParadoxGameConverters/Fronter.NET/issues/602">#602</a>)</li>
<li>See full diff in <a
href="https://github.com/ParadoxGameConverters/Fronter.NET/compare/5c996a1dd121fcc2eab975fae2f25d636c843096...af6846f1ac45c399a3881b168304ec7ca4ef1fe0">compare
view</a></li>
</ul>
</details>
<br />


Dependabot will resolve any conflicts with this PR as long as you don't
alter it yourself. You can also trigger a rebase manually by commenting
`@dependabot rebase`.

[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)

---

<details>
<summary>Dependabot commands and options</summary>
<br />

You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits
that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after
your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge
and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating
it. You can achieve the same result by closing it manually
- `@dependabot show <dependency name> ignore conditions` will show all
of the ignore conditions of the specified dependency
- `@dependabot ignore this major version` will close this PR and stop
Dependabot creating any more for this major version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop
Dependabot creating any more for this minor version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop
Dependabot creating any more for this dependency (unless you reopen the
PR or upgrade to it yourself)


</details>

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>