Regenerate decam linearizer files with python3

The decam linearizer files we have commited to obs_decam are pickles files produced with python2, and required a fix to daf_persistence to specify an encoding:

if sys.version_info.major >= 3:

    finalItem = pickle.load(infile, encoding="latin1")

else:

    finalItem = pickle.load(infile)

I believe that we can fix this by just re-running makeLinearizer.py on python 3, to get the encoding explicitly specified, but I'm not certain.

Once done, we should probably remove that encoding specification from daf_persistence. It would also be a chance to fix the file naming in DM-8219.