Supplementary physics updates for RRFS code freeze

[haiqinli]

Description

Provide a detailed description of what this PR does. What bug does it fix, or what feature does it add?

MYNN: 1) cosmetic fix to the cloud fractions in (relatively rare) conditions with unsaturated grid cells and positive mixing ratios; 2) very slight increase in diffusion in stable conditions; 3) momentum transport bug fix--missing rho.
RUC LSM: Computation of the new snow fraction uses now snow with variable density to reduce cold bias.
GF: Adjust the scale-awareness in the 1st hour forecast to reduce precipitation bias.
Smoke and Dust: Fix the diurnal cycle of smoke, dust emission over frozen soil, dry deposition.

Is a change of answers expected from this PR?
Yes.

Testing

How were these changes tested? Regression test
What compilers / HPCs was it tested with? Intel/Hera

Are the changes covered by regression tests? (If not, why? Do new tests need to be added?)
Yes. No new testes are needed.

Have the ufs-weather-model regression test been run? On what platform? Yes, on Hera.

• Will the code updates change regression test baseline? If yes, why? Please show the baseline directory below.
  Yes, the results are changed by physics updates. /scratch2/BMC/acomp/Haiqin.Li/stmp4/Haiqin.Li/FV3_RT/rt_112955
• Please commit the regression test log files in your ufs-weather-model branch. Committed.

Dependencies

If testing this branch requires non-default branches in other repositories, list them.
Those branches should have matching names (ideally)

Do PRs in upstream repositories need to be merged first? No

[DusanJovic-NOAA]

This PR depends on ccpp-physics, please list the corresponding ccpp PR in the Dependencies section of the description.

[grantfirl]

This PR depends on ccpp-physics, please list the corresponding ccpp PR in the Dependencies section of the description.

@DusanJovic-NOAA This PR was combined into #682.

[DusanJovic-NOAA]

Merged via #682