allocate heat_source when SKEB is True and d_con is zero

[NeilBarton-NOAA]

Description

The model fails when d_con is zero and skeb is True because heat_source is unallocated. This change allocates heat_source when skeb is True

Fixes # (issue)

No issue previously assigned.

How Has This Been Tested?

The code has been tested in the gefs forecasting in g-w. Currently testing rt.

Checklist:

Please check all whether they apply or not

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

[lharris4]

Looks good to me. Thanks for submitting this change.

[FernandoAndrade-NOAA]

#2278 is ready, please continue with the merge process, thank you.

[bensonr]

@NeilBarton-NOAA - Did you create an issue for this PR? I want to make sure it gets closed.

[NeilBarton-NOAA]

@bensonr I did not.