Remove hits with no energy deposits in pet_to_stp

[fhagemann]

When reading in GEANT4 files, some hits might not have energy deposits.
They might also not be worth drifting as they will not contribute to the final waveform.
Merging this PR would remove these hits in pet_to_stp

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: -0.03% ⚠️

Comparison is base (eaae6ee) 13.60% compared to head (2aa6a5c) 13.58%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #44      +/-   ##
==========================================
- Coverage   13.60%   13.58%   -0.03%     
==========================================
  Files          22       22              
  Lines         669      670       +1     
==========================================
  Hits           91       91              
- Misses        578      579       +1     

Files Changed	Coverage Δ
src/pet_to_stp.jl	0.00% <0.00%> (ø)

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[sagitta42]

Our original idea was to somehow preserve the "original" event ID to be able to compare later performance of A/E cut, for example, based on the "truth" information. So, for example, in the pss->raw part, if the pulse doesn't trigger, it is not simply removed from the final raw file, but is replaced with an all-zero "waveform" to preserve the number of events.

So, this said, in cases where there are hits that don't have energy deposition (how is that even possible, by the way?..), those hits are not the only ones in the event? As in, there aren't events that are somehow "zero-deposition" events, consisting only of such hits that will be removed?

[oschulz]

Good to merge from my side.