Disable isomorphous check in `matchmaps.diagnose`

[dennisbrookner]

The offending line of code is here:

matchmaps/src/matchmaps/_diagnostic_plots.py

Line 52 in 32d638d

mtz = offmtz.merge(onmtz, on=["H", "K", "L"], suffixes=("_off", "_on"))

The merge function needs the parameter check_isomorphous=False. Otherwise, reciprocalspaceship will refuse to merge the two DataSets together if they aren't strictly isomorphous. When using matchmaps.diagnose, this will frequently be the case!!!