✨ Prepare janitor for initial version

[salasberryfin]

Description

This PR adds new functionalities and refactors the rules for deletion:

• ignore-tag input parameter: name of the tag that indicates a resource should not be deleted. If not provided, it uses a sensible default janitor-ignore.
• ttl is no longer used for deletion since janitor now manages deletion of resources that do not have a creation time associated with them. The new approach is mark and delete: the initial execution will mark (using tag aws-janitor/marked-for-deletion) for future deletion on all resources that do not have an ignore tag. Next execution will apply deletion on marked resources.
• Supported resources are (in this strict order): EKS Clusters, Auto Scaling Groups, Load Balancers, Security Groups, CloudFormation Stacks. This order is required because of dependencies between resources.

In some specific scenarios, intermittent failures may occur due to dependent resources but these should be fixed in subsequent iterations.

Comments

After this PR is merged, we'll need to add the janitor to the existing GitHub Action.

Deletion of Security Groups is required for VPC to be deleted from the CloudFormation stack. AWS seems to be slow to delete Security Groups and ingress/egress rules, which can make one Security Group dependent on another. Since there's no way in the SDK to wait for SGs to be deleted, there needs to be a Sleep added between triggered deletions. The number of SGs should always be manageable so this is not expected to noticeably affect time of execution.