TypeError in core.extract._calc_resampled_time_coord() #179

Found by GHA pytest-with-coverage workflow for all supported Python versions.

Almost certainly a result of the release of pandas=3.0.0. This may be a consequence of the change to consistently handle days across Daylight Savings Time transitions whereby "pandas.tseries.offsets.Day no longer supports division".

Traceback:

>           offsets = pandas.tseries.frequencies.to_offset(freq) / 2
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
E           TypeError: unsupported operand type(s) for /: 'pandas._libs.tslibs.offsets.Day' and 'int'

reshapr/core/extract.py:1004: TypeError