Remove is_in_microsim checks from benefit variables

[MaxGhenis]

Summary

Following PR #7326 which moved all stochastic randomness to the data package, benefit variables no longer need special is_in_microsim handling for takeup.

Since takeup variables now have default_value = True, we can always multiply by takeup:

• Individual simulation: takeup defaults to True (1), benefit unchanged
• Microsimulation: data package sets actual takeup values

Files to update

snap.py still has:

is_in_microsim = hasattr(spm_unit.simulation, "dataset")
...
if is_in_microsim:
    return value * takes_up
else:
    return value

Should be simplified to:

return value * takes_up

Related

• PR Move all stochastic randomness to data package for deterministic country package #7326: Move all stochastic randomness to data package
• PR Add liquid asset variables for SSI modeling #7329: SSI already uses simplified pattern