Enable building contributed recipes in PRs

[mathbunnyru]

Describe your changes

Issue ticket if applicable

Checklist (especially for first-time contributors)

• I have performed a self-review of my code
• If it is a core feature, I have added thorough tests
• I will try not to use force-push to make the review process easier for reviewers
• I have updated the documentation for significant changes

[mathbunnyru]

With this change contributed recipes stage will run in parallel to pushing tags and merging tags, so we should decrease time it takes to build everything and then the contributed recipes.

[mathbunnyru]

In this PR I change both contributed-recipes and docker workflows.

This means that contributed-recipes runs twice :

1. It is triggered because PR changes the workflow file. It runs using images already pushed to the registry: https://github.com/jupyter/docker-stacks/actions/runs/13377348557/job/37359262602?pr=2213
2. As part of docker.yml workflow. This doesn't use registry at all and uses images built during running docker.yml: https://github.com/jupyter/docker-stacks/actions/runs/13377348556/job/37359703793?pr=2213