investigate commented-out phenology in do_conversions

[infotroph]

Code in workflow::do_conversions:

if (input.tag == "leaf_phenology" && is.null(input$path)) {
      # settings$run$inputs[[i]]$path <- PEcAn.data.remote::extract_phenology_MODIS(
      #   site_info,
      #   start_date,
      #   end_date,
      #   outdir,
      #   run_parallel = TRUE,
      #   ncores = NULL
      # )
      needsave <- TRUE
    }

@mdietze in #3407 (comment) :

Not sure why this bit is commented out -- seems like something we need to be operational