`GCSToLocalFilesystemOperator` in `airflow/providers/google/cloud/transfers/gcs_to_local.py` checks the file size if `store_to_xcom_key` is `True`.

https://github.com/apache/airflow/blob/b40dffa08547b610162f8cacfa75847f3c4ca364/airflow/providers/google/cloud/transfers/gcs_to_local.py#L137-L142

How it checks size is to download the object as `bytes` then check the size. This unnecessarily downloads the objects. `google.cloud.storage.blob.Blob` itself already has a `size` property ([documentation reference](https://googleapis.dev/python/storage/1.30.0/blobs.html#google.cloud.storage.blob.Blob.size)), and it should be used instead.

In extreme cases, if the object is big size, it adds unnecessary burden on the instance resources.

A new method, `object_size()`, can be added to `GCSHook`, then this can be addressed in `GCSToLocalFilesystemOperator`.
airflow/providers/google/cloud/transfers/gcs_to_local.py
"""
    Downloads a file from Google Cloud Storage.
    If a filename is supplied, it writes the file to the specified location, alternatively one can
    set the ``store_to_xcom_key`` parameter to True push the file content into xcom. When the file size
    exceeds the maximum size for xcom it is recommended to write to a file.
    .. seealso::
        For more information on how to use this operator, take a look at the guide:
        :ref:`howto/operator:GCSToLocalFilesystemOperator`
    :param bucket: The Google Cloud Storage bucket where the object is.
        Must not contain 'gs://' prefix. (templated)
    :type bucket: str
    :param object_name: The name of the object to download in the Google cloud
        storage bucket. (templated)
    :type object_name: str
    :param filename: The file path, including filename,  on the local file system (where the
        operator is being executed) that the file should be downloaded to. (templated)
        If no filename passed, the downloaded data will not be stored on the local file
        system.
    :type filename: str
    :param store_to_xcom_key: If this param is set, the operator will push
        the contents of the downloaded file to XCom with the key set in this