Remove last remnants of visualization_old

[rht]

No description provided.

[github-actions]

Performance benchmarks:

Model	Size	Init time [95% CI]	Run time [95% CI]
Schelling	small	🔵 +0.9% [+0.6%, +1.3%]	🔵 -0.3% [-0.5%, -0.1%]
Schelling	large	🔵 +1.1% [+0.2%, +1.9%]	🔵 -0.9% [-1.7%, -0.2%]
WolfSheep	small	🔵 +0.3% [-0.9%, +1.6%]	🔵 +0.3% [-0.1%, +0.6%]
WolfSheep	large	🔵 +0.2% [-0.1%, +0.4%]	🔵 -0.3% [-1.2%, +0.8%]
BoidFlockers	small	🔵 +2.8% [+2.0%, +3.8%]	🔵 +0.7% [+0.1%, +1.2%]
BoidFlockers	large	🔵 +3.3% [+2.4%, +4.1%]	🔵 +0.4% [-0.4%, +1.1%]

[EwoutH]

Thanks!