Update calibration uncertainties

[bendavid]

This adds the statistical uncertainty from the jpsi calibration inflated by sqrt(7.2) to enforce chi^2/dof=1 in the parameterized closure test.

The dummy 7.5e-5 calibration uncertainty is reduced to 6.8e-5 to maintain approximately the same overall impact in the fit for the moment.

[bendavid]

This looks as expected for the PRValidation, but I'm triggering the high stats run to get absolute numbers.

[bendavid]

The three sets of uncertainties behave as expected in the CI (inflated jpsi stat uncertainty, 6.8e-5 dummy uncertainty, and stat uncertainties from the Z-derived resolution corrections)

So this would be ready to merge now as an intermediate update of the calibration uncertainties (but almost certainly closer to the final setup than what is currently in main where there are no statistical uncertainties on the calibration included)