Blender Git Loki

Fix issues with absolute time unit

I think there are the following issues with {rB5fa6cdb77a98}:
- if we introduce a PROP_UNIT_TIME_ABSOLUTE unit, shouldnt it be visible
to RNA as well?
- seems like a double entry sneaked into that commit?

This is in preparation to use this for render time limit in cycles-x.

ref. T90701

Maniphest Tasks: T90701

Differential Revision: https://developer.blender.org/D12315