DEPR: Remove xlrd as being the default reader for xlsx
Currently the default reader for xlsx is openpyxl if installed, otherwise it is xlrd. While xlrd == 1.2.0 will work with xlsx files, xlrd >= 2.0 will not. In pandas 1.2, a FutureWarning is raised if xlrd is used on non-xls files. We should remove xlrd as being the default for xlsx files in pandas 2.0, but perhaps even 1.3 (if 1.3 != 2.0).

cc @jorisvandenbossche