Bump pandas from 1.2.3 to 1.2.4

[dshemetov]

Currently getting these warnings whenever Pandas calls SQL library functions

=============================== warnings summary ===============================
repos/delphi/delphi-epidata/integrations/acquisition/covidcast_nowcast/test_csv_uploading.py::CsvUploadingTests::test_duplicate_row
repos/delphi/delphi-epidata/integrations/acquisition/covidcast_nowcast/test_csv_uploading.py::CsvUploadingTests::test_duplicate_row
repos/delphi/delphi-epidata/integrations/acquisition/covidcast_nowcast/test_csv_uploading.py::CsvUploadingTests::test_uploading
  /usr/local/lib/python3.8/site-packages/pandas/io/sql.py:1429: SADeprecationWarning: The Engine.run_callable() method is deprecated and will be removed in a future release.  Use the Engine.begin() context manager instead. (deprecated since: 1.4)
    return self.connectable.run_callable(

Bumping to pandas==1.2.4 removes these warnings.

[dshemetov]

Oops this is a duplicate of #992.