[glemieux]

This update the FATES gitmodule fxtag to point to the FATES maintenance branch release

Description of changes

Specific notes

Contributors other than yourself, if any:

• (Replace this text and add more list items as needed)

CTSM issues resolved or otherwise addressed, if any:

Resolves #4038
Resolves #4039

If answers are expected to change, describe (delete this line otherwise):

Any user interface changes (namelist or namelist defaults changes)?

Testing planned or performed, if any:

• (Replace this text and add more list items as needed)

Requirements before merge:

• I have followed the CTSM contribution guidelines.

• The code in this PR branch builds with no errors.
• The code in this PR branch runs with no errors. Briefly describe tested configuration(s):
• This either (a) does not change answers, (b) it only changes answers at roundoff level, or (c) I have performed a scientific evaluation of the answer changes. Which?:

• I have reviewed relevant parts of the CLM documentation Tech Note or User's Guide to determine if anything needs to be changed or added. If it does, describe:
• This PR either (a) does not create a need to update the documentation or (b) includes required documentation updates (see guidelines for contributing documentation). Which?: