Address FutureWarnings in Sycamore

[hackdna]

  /home/runner/work/forest/forest/forest/sycamore/common.py:417: FutureWarning: Series.fillna with 'method' is deprecated and will raise in a future version. Use obj.ffill() or obj.bfill() instead.
    df_merged["config_id_update"] = df_merged["config_id"].fillna(

forest/sycamore/tests/test_functions.py::test_summarize_submits_hour
  /home/runner/work/forest/forest/forest/sycamore/submits.py:528: FutureWarning: 'H' is deprecated and will be removed in a future version, please use 'h' instead.
    submits["delivery_time_floor"] = submits["delivery_time"].dt.floor("H")