Fix bug in QEE Gamma{LL,DD}Jet sprucing lines

Discovered that the rate of these lines was 0 even though they should be pass-through on HLT2 lines that have non-zero rate.

Seems to be a python scoping quirk - the photon_type variable has changed value by the time the function is called. This is fixed by copying the variable via a parameter default - this freezes it at definition time.

Follow-up checks are needed across at least the QEE code that there aren't more such bugs like this.

• Will undraft once I've checked again.