remove helper functions dealing with maps

### Describe what should be investigated or refactored

Now that https://pkg.go.dev/maps exists, there is no need for certain functions in `helpers` to exist. They should be deprecated and return the upstream `maps` versions of their operations.

### Links to any relevant code

https://github.com/defenseunicorns/pkg/blob/fa0230ec27f11d6ab14d5921395a740f5ede504f/helpers/misc.go#L40