Address pandas `SettingWithCopyWarning`

[thorwhalen]

In cosmograph==1.0.0b1:

This warning always comes up on first run of cosmo:

/Users/thorwhalen/.pyenv/versions/3.12.12/envs/p12/lib/python3.12/site-packages/cosmograph/widget/utils.py:27: SettingWithCopyWarning: 
A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_indexer,col_indexer] = value instead

See the caveats in the documentation: https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy
  df[df_int32.columns] = df_int32

Here's where the error occurs:

@memory.cache
def get_buffered_arrow_table(df):
  """Converts a Pandas DataFrame to a buffered Arrow IPC stream format.

  This function is cached using joblib.Memory.
  """

  if df is None:
      return None
  try:
      df_int32 = df.select_dtypes(include=["int64"]).astype("int32")
      df[df_int32.columns] = df_int32  # <--- HERE. 
      table = pa.Table.from_pandas(df)
      sink = pa.BufferOutputStream()

I can't find the github branch corresponding to cosmograph==1.0.0b1, but anyway, AI will help you repair this in minutes.