Various FutureWarnings in logs for downcasting objects

[Flix6x]

Specifically, in these places (for Python 3.10), since flexmeasures==0.24:

/usr/local/lib/python3.10/dist-packages/timely_beliefs/beliefs/utils.py:1183: FutureWarning: BeliefsDataFrame.fillna with 'method' is deprecated and will raise in a future version. Use obj.ffill() or obj.bfill() instead.
  df = df.fillna(
/usr/local/lib/python3.10/dist-packages/flexmeasures/data/models/planning/storage.py:986: FutureWarning: Setting an item of incompatible dtype is deprecated and will raise an error in a future version of pandas. Value '0.05015 MWh' has dtype incompatible with float64, please explicitly cast to a compatible dtype first.
  device_values.loc[soc_constraint_start:end_of_schedule] = soc
/usr/local/lib/python3.10/dist-packages/flexmeasures/data/models/planning/storage.py:1087: FutureWarning: Downcasting object dtype arrays on .fillna, .ffill, .bfill is deprecated and will change in a future version. Call result.infer_objects(copy=False) instead. To opt-in to the future behavior, set `pd.set_option('future.no_silent_downcasting', True)`
  storage_device_constraints["max"] = storage_device_constraints["max"].fillna(
/usr/local/lib/python3.10/dist-packages/flexmeasures/data/models/planning/storage.py:1302: FutureWarning: Downcasting object dtype arrays on .fillna, .ffill, .bfill is deprecated and will change in a future version. Call result.infer_objects(copy=False) instead. To opt-in to the future behavior, set `pd.set_option('future.no_silent_downcasting', True)`
  lhs = constraints_df.fillna(0).eval(lhs_expression).round(round_to_decimals)
/usr/local/lib/python3.10/dist-packages/flexmeasures/data/models/planning/storage.py:1303: FutureWarning: Downcasting object dtype arrays on .fillna, .ffill, .bfill is deprecated and will change in a future version. Call result.infer_objects(copy=False) instead. To opt-in to the future behavior, set `pd.set_option('future.no_silent_downcasting', True)`
  rhs = constraints_df.fillna(0).eval(rhs_expression).round(round_to_decimals)
/usr/local/lib/python3.10/dist-packages/flexmeasures/data/models/planning/linear_optimization.py:216: FutureWarning: Downcasting object dtype arrays on .fillna, .ffill, .bfill is deprecated and will change in a future version. Call result.infer_objects(copy=False) instead. To opt-in to the future behavior, set `pd.set_option('future.no_silent_downcasting', True)`
  ].fillna(0)