The deaths from covid are defined as”total number of deaths since the start of the pandemic of people whose death certificate mentioned COVID-19 as one of the causes.” There is no reference to positive tests. See the earlier discussion in this thread about death certification.
The UK population in 2019 was not 68M but 66.4M. Using the correct figure would give a slightly higher crude death rate at approx 9.1 deaths/1000 population. I think the point still stands however.