Make local repository higher priority than default

[HebaruSan]

Problem

KSP-CKAN/NetKAN#9806 is failing validation because the validator is trying to install the old version of the module, without the PR's changes:

https://github.com/KSP-CKAN/NetKAN/actions/runs/6249249066/job/16965475746?pr=9806

https://github.com/KSP-CKAN/NetKAN/pull/9806/files

Cause

The validator adds the changes as a repo named local, and its priority ends up being 1, with the default repo remaining 0 priority. This means the default version of the module takes precedence.

This worked previously because priority was not used and the sort was alphabetical, so default was overridden by local.

Changes

Now we set the priority of the local repo to 0, so the PR's changes will override the default repo.

I'll self-review this so I can see if it helps that PR.

[HebaruSan]

Worked.

https://github.com/KSP-CKAN/NetKAN/actions/runs/6249249066/job/16970655335

(The validator doesn't install virtual dependencies, unfortunately.)