recom forcing files needed in both ocean-only and coupled

[chrisdane]

In 7e22dcf, recom forcing routines were transferred from recom to gen_surface_forcing.F90s sbc_do, e.g.

! ******** Fe deposition *********
    if (fe_data_source=='Albani') then
        if (update_monthly_flag) then
            if (mype==0) write(*,*) 'Updating iron climatology for month       ', i,' from ', trim(filename)

Until today, recom expects these forcing files, no matter if ocean-only or coupled mode.

@a270105 now realized that sbc_do is only called in ocean-only, and not in coupled mode. Hence, during the coupled run the recom forcing fields stay nan and and added to the rhs, why the output (e.g. aFe) is also nan.

@ogurses @JanStreffing: In current main 45026e5, the recom block in gen_surface_forcing.F90:L1661ff needs to be called in both modes, ocean-only and coupled 🙏