Fix variable-length array logical (``PL``/``QL``) columns being written as 1/0 bytes instead of FITS T/F and read back as raw int8 (84/70) instead of bool. Files written by astropy <= 7.2.0 (which used the legacy 0x00/0x01 encoding) are still readable: such files are detected on read and decoded correctly with an ``AstropyUserWarning``.
