KLM, AF, SAS, Lufthansa and Turkish all fly to either GLA or EDI and would avoid LHR.

Aer Lingus is an option too, either connecting or a round trip and book a separate DUB - EDI/GLA on easyJet or Ryanair.

If you are really desperate and prepared for a long diversion, you could also look at Qatar or Emirates.

Plenty ways to avoid LHR here.