Remove call of LoadInstrumentFromNexus re #9996

Placeholder kept in comments

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>
Remove runLoadInstrumentFromNexus re #9996

and reference to LoadInstrumentFromNexus

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>
Merge remote-tracking branch 'origin/feature/9996_load_instrument_form_nexus_removal'