Fix incorrect UT strip index in decoding [v57r16-patches, 2025 EoY Sprucing MC]
Backport of !2178
See report: https://indico.cern.ch/event/1565010/#4-run3-detectors-status-and-pl
The strip index in flipped UT sensors was off by 1 (slide 7).
To be tested together with LHCb!5460 (merged)