replace shr_file with shr_log

[jedwards4b]

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PR checklist

• Short (1 sentence) summary of your PR:
  Replace depricated shr_file with shr_log
• Developer(s):
  Jim Edwards
• Suggest PR reviewers from list in the column to the right.
• Please copy the PR test results link or provide a summary of testing completed below.
  In cesm if you run with the current cice you get messages:
  /glade/work/jedwards/sandboxes/cesm3_0_x/share/src/shr_file_mod.F90 913 This routine is depricated - use shr_log_setLogUnit instead

By updating to shr_log_setLogUnit these messages are no longer printed and the ice.log file is otherwise identical to previous.

• How much do the PR code changes differ from the unmodified code?
  • bit for bit
  • different at roundoff level
  • more substantial
• Does this PR create or have dependencies on Icepack or any other models?
  • Yes
  • No
• Does this PR update the Icepack submodule? If so, the Icepack submodule must point to a hash on Icepack's main branch.
  • Yes
  • No
• Does this PR add any new test cases?
  • Yes
  • No
• Is the documentation being updated? ("Documentation" includes information on the wiki or in the .rst files from doc/source/, which are used to create the online technical docs at https://readthedocs.org/projects/cice-consortium-cice/. A test build of the technical docs will be performed as part of the PR testing.)
  • Yes
  • No, does the documentation need to be updated at a later time?
    • Yes
    • No
• Please document the changes in detail, including why the changes are made. This will become part of the PR commit log.
  shr_file_getLogunit has been deprecated and will be removed prior to the cesm3 release.