feat(GitHub): add support for new GitHub project

[juliapampus]

What this PR changes/adds

Unify old actions for assigning PRs and issues to a new one. Replaced action type.

Why it does that

The classic project was migrated to a new one: https://github.com/orgs/eclipse-edc/projects. With this, a new project number was created. In addition, the old action does not support the new GitHub projects API.

Further notes

Could happen that we again face issues regarding PR assignments. As we are creating PRs from forks, the event type pull_request_target instead of pull_request had to be used with the old action. According to the readme and issues, this may not be supported by the new action yet. We have to try it out.

Linked Issue(s)

Relates #2356

Checklist

• added appropriate tests?
• performed checkstyle check locally?
• added/updated copyright headers?
• documented public classes/methods?
• added/updated relevant documentation?
• assigned appropriate label? (exclude from changelog with label no-changelog)
• formatted title correctly? (take a look at the CONTRIBUTING and Etiquette for pull requests for details)