dotproducttest.cc: avoid `sqrt(-1.0f)`

enabled an automatic merge when the pipeline for 46075a6c succeeds

mentioned in commit c55d5167

merged

mentioned in issue #58 (closed)

mentioned in merge request !261 (merged)

mentioned in commit ff362d90

mentioned in commit 28a423f6

mentioned in commit 6cd96994

mentioned in commit 8f33d649