fix(dependabot): add support for cargo and pub registries

[SoaAlex]

GitHub supports 2 (new) registires in Dependabot custom registry yaml configuration.

There were missing from the current V2 schema (all schemas >=V2 support these ones)

According to this documentation

EDIT:
GitHub docs seem to have a typo.
I'm using the custom pub registry, but GitHub returns an error if setting pub-registry like in the docs, instead of pub-repository.
Here's the sample error:

The property '#/registries/pub-jfrog/type' value "pub-registry" did not match one of the following values: cargo-registry, composer-repository, docker-registry, git, helm-registry, hex-organization, hex-repository, maven-repository, npm-registry, nuget-feed, pub-repository, python-index, rubygems-server, terraform-registry

Therefore, I can confirm regarding the error, and local testing, that it should be pub-repository.

[github-actions]

Thanks for the PR!

This section of the codebase is owned by @madskristensen and @hyperupcall - if they write a comment saying "LGTM" then it will be merged.

[hyperupcall]

Thanks