Update snwredist documentation, update Icepack to #68097c59aceb20 (#1100)

Update snwredist documentation
Update snwredist setting in set_nml.cesm3
Update icepack to #68097c59aceb20 Apr 9, 2026 includes update to snwredist documentation

Author: apcraig

configuration/scripts/options/set_nml.cesm3

@@ -3,7 +3,7 @@ congel_freeze = 'one-step'
 hist_time_axis = 'middle'
 nfsd = 12
 nfreq = 25
-snwredist = "snwITDrdg"
+snwredist = "ITDrdg"
 tr_fsd = .true.
 tr_ponds_lvl = .false.
 tr_ponds_sealvl = .true.

doc/source/user_guide/ug_case_settings.rst

@@ -644,7 +644,6 @@ snow_nml
    "``snwgrain``", "logical", "snow metamorophsis flag", "``.false.``"
    "``snwlvlfac``", "real", "fractional increase in snow", "0.3"
    "``snwredist``", "``bulk``", "bulk snow redistribution scheme", "``none``"
-   "", "``ITD``", "ITD snow redistribution scheme", ""
    "", "``ITDrdg``", "ITDrdg snow redistribution scheme", ""
    "", "``none``", "snow redistribution scheme off", ""
    "``snw_aging_table``", "'file'", "read 1D and 3D fields for dry metamorophsis lookup table", "test"