Pramen-Py get_latest_available_date throws an error for delta tables

[jirifilip]

Describe the bug

For some reason, in get_latest_available_date, reading the partitioning column of a delta table produces a list of strings instead of datetime.date. But we rely on it returning list of dates, so the method fails.

Failing test case

This test case passes for parquet but fails for delta

@pytest.mark.parametrize("table_format", (TableFormat.parquet, TableFormat.delta))
def test_get_latest_available_date(
        spark,
        tmp_path,
        table_format
):
    test_table_df = spark.createDataFrame([
        (1, "John", d(2023, 3, 23)),
        (2, "Jack", d(2023, 3, 23))
    ]).toDF("id", "name", "info_date")
    metastore_table = MetastoreTable(
        name="test_table",
        format=table_format,
        path=tmp_path.as_posix(),
        info_date_settings=InfoDateSettings(column="info_date"),
    )
    writer = MetastoreWriter(
        spark=spark,
        tables=[metastore_table],
        info_date=d(2022, 3, 23),
    )
    writer.write("test_table", test_table_df)

    metastore_reader = MetastoreReader(spark=spark, tables=[metastore_table])
    latest_available_date = metastore_reader.get_latest_available_date("test_table") # delta fails here

    assert type(latest_available_date) == datetime.date

Expected behavior

Test should pass for both parquet and delta