Remove old benchmarks
c.f.: https://foss.heptapod.net/fluiddyn/fluidsim-bench-results for the right results used in the fluidsim article
This instance will be upgraded to Heptapod 17.9.0rc1 on 2025-03-27 between 17:00 and 18:00 UTC+2
c.f.: https://foss.heptapod.net/fluiddyn/fluidsim-bench-results for the right results used in the fluidsim article