Throw a warning if pfsConfig0 coudn't be found

We noticed with Craig the other day, that most of the visits on _2026-01-09 _have the wrong pfsConfig. one example :

2026-01-09 05:28:23.720Z pfsField         30 pfsField.py:131 [Errno 2] No such file or directory: '/data/raw/tests/pfsConfig/pfsConfig-0x427bd9be742aaa2d-136657.fits'

What happened is that a tests directory was created in_ /data/raw_ after the date directory was created 2026-01-09, so it was detected by iic as the most recent day, and that's where iic was trying to match pfsConfig but fps was not writing there of course.
So iic couldn't load the correct pfsConfig0 and made copy of the PfsDesign as a result.

I already pushed a fix to ics_utils to make the date pattern more robust, but I should throw a critical warning, because it's pretty bad.