The CI would only detect a deviation from the normalized value based on
a configurable threshold, typically 1.25 (so we would tolerate a 25%
increase). However, it often happens that a timing gets shorter (e.g.,
forgot to put the timing measurements). This commit introduces a
"Deviation Threshold" (smaller than 1) to not only check that we exceed
1.0 + "Deviation Threshold" (as before), but also that are not below 1.0
- "Deviation Threshold".

In other words, assuming a maximum divergence of 25%, instead of just
checking if val > 1.25, we now also check if val < 0.75 (and flag
error).