[Bug]: another fix for age discard

[Rick-Methot-NOAA]

Describe the bug

Age-based selection option 1 for Discard does not appear to be working correctly. In my tests the sel_bio is greater than the dead_bio and the dead_bio is equal to the ret_bio. I think the expected behavior would be that the sel_bio would be equal to the dead_bio

To Reproduce

see Chantel's example

Expected behavior

correct performance of retention functions

Screenshots

No response

Which OS are you seeing the problem on?

No response

Which version of SS3 are you seeing the problem on?

No response

Additional Context

No response