Update e3sm project

[xylar]

This merge updates the E3SM-Project submodule from 20784fb to de075c7.

This update includes the following MPAS-Ocean and MPAS-Frameworks PRs (check mark indicates bit-for-bit with previous PR in the list):

• (ocn) remove unused variables in ocean E3SM-Project/E3SM#5610

Checklist

• The E3SM-Project submodule has been updated with relevant E3SM changes
• Document (in a comment titled Testing in this PR) any testing that was used to verify the changes

closes #500
closes #497

[xylar]

Testing

I used the utility in utils/e3sm_update to run the pr test suite comparing the previous E3SM-Project submodule with the current one that brings in E3SM-Project/E3SM#5610. My tests were with Intel and OpenMPI on Chrysalis so they passed both before and after the changes. (Gnu tests would have been expected to fail before the update.)

[xylar]

Thank you for the fix in E3SM-Project/E3SM#5610, @mark-petersen!