Always record the output collections, even if they are empty.

[scott-snyder]

The output code decides what to write based on the contents of the first event. If we don't always record the collections, then they can either be missing in the output, or we can get crashes when the output code tries to access a nonexistent collection.

BEGINRELEASENOTES

• Always record the output collection, even they are empty. Avoids crashes from PodioOutput.
  ENDRELEASENOTES

[scott-snyder]

I ran into this processing a CLD full-sim (Z->jets)(H->inv) sample with the
2023-11-30-yi2hqy release, running the reconstruction using the
CLDReconstruction.py script from CLDConfig. The sample of 20000 events
was split into 20 jobs of 1000 events each. About 30% of the jobs crashed
in the first few events with the error

PodioOutput         ERROR Could not write event, because the following collections are not present: LumiCalClusters, LumiCalClusters_particleIDs, LumiCalRecoParticles, LumiCalRecoParticles_particleIDs

while the remainder ran to completion.

I can make available the simulation output for one of the failing jobs
if desired.

[andresailer]

Thanks @scott-snyder !