dotty-bench.epfl.ch sometimes records running time of 0 seconds, skewing moving average

[smarter]

Lately, https://dotty-bench.epfl.ch has looked pretty eratic:

Zooming out and enabling "min", we see that some points are incorrectly recorded as 0 second long:

[Gedochao]

cc @mbovel @hamzaremmal

[mbovel]

Sorry this issue has been standing for so long. I plan to clean up the data when merging the new visualiser (#21720) and the new benchmarks infrastructure (#21719). This should be done in a few weeks.