Skip delete of labels

[anderssonjohan]

I took the labels plugin for a spin yesterday and noticed it will remove any labels created manually.
I, for example, have other bots that create labels automatically, such as semantic release which creates labels such as "released", "released on @dev" and more specifically for backports, dynamic labels such as "released on @6.x.x".
These labels allow us to know what's released in a backport and on main, etc., so it's crucial for us to keep these dynamically created labels.

But I still want to manage a good baseline of labels for a suborg with Safe Settings.

What do you think would be the best option here?

I'm thinking that adding an opt-in behavior to skip label deletes would be the solution in my scenario.
This opt-in behavior could be activated using settings.yml or deployment-settings.yml by adding:

labels_config:
  delete: false

How does that sound to you @decyjphr @martinm82? Do you have any suggestions, before I start a PR?
I'm thinking labels_config or labels_settings is a good option for a config key name to avoid changing the current config format of the labels plugin (currently a list).