Fix various usages of MOI.delete · jump-dev/MultiObjectiveAlgorithms.jl@67467ce

Failed to save: reserveCache failed: Cache service responded with 503

Failed to restore: getCacheEntry failed: Cache service responded with 503

[setup-julia] If you are testing 1.6 as a Long Term Support (lts) version, consider using the new "lts" version specifier instead of "1.6" explicitly, which will automatically resolve the current lts.