Removing secrets should not block auto-merged

[heurtematte]

Related to this PR: eclipse-dataspace-hub/.eclipsefdn#2

This PR removes all secrets from a repository, but it received the following warning from the otterdog bot account:

The auto-merge behavior should be more finely tuned for GitHub organization and repository secrets.

In particular, it should distinguish between:

• adding or updating secrets, which may require additional validation or approval, and manual setup;
• removing secrets, should generally be safe to auto-merge, since we are using soft deletion.

[heurtematte]

I just found out that this doesn't perform a soft deletion.

Is this configured somewhere, in [EclipseFdn/otterdog-configs](https://github.com/EclipseFdn/otterdog-configs)?

With the otterdog client, resources are kept in place unless --delete-resources is explicitly specified.

Could we align these behaviors?

[netomi]

PRs that are merged will delete resources, so it runs explicitly with --delete-resources otherwise you would have to manually run apply for many PRs. The logic is like that in case you delete a resource it needs to be approved first. However this was a simplification to prevent auto-merge for any deletion. We could change that such that only the deletion of repositories needs to be approved as this is the only destructive operations afaict, all other things can be recovered.