Update the E3SM-Project submodule

[xylar]

This merge updates the E3SM-Project submodule from 31f771c to c7d7998.

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

• [x] (ocn) https://github.com/E3SM-Project/E3SM/pull/6472
• [x] (ocn) https://github.com/E3SM-Project/E3SM/pull/6471
• [ ] (ocn) https://github.com/E3SM-Project/E3SM/pull/6481 -- as expected, there are non-BFB differences in all global ocean forward runs due to the chantes in Omega and pi. The changes are of order 1e-6 to 1e-8, so small but definitely not at machine percision

[xylar]

It seems like I jumped the gun on matplotlib 3.9.0 in #838. It appears to have been published erroneously and we're still waiting on an official release on conda-forge (which will actually be 3.9.1: https://github.com/conda-forge/matplotlib-feedstock/pull/390).

To make progress with this testing in the meantime, I temporarily allowed 3.8.4 in my local checkout and that also seemed to work fine.