combine_run_metrics throws removed combined file warning on each FOV run through the watcher

[alex-l-kong]

Is your feature request related to a problem? Please describe.

Each time a new FOV is detected by the watcher and the MPH pipeline runs, the _combined.csv file gets removed and regenerated, but this also comes with a warning that indicates this happens. If the run contains a substantial amount of FOVs, this warning will pop up for each one except the first (with 50, this can get very wordy).

Describe the solution you'd like

There should at the very least be a flag that turns this off for the watcher. We could consider using verbose or something else.

Honestly, I wouldn't be against just removing the warning entirely either.