Correct wolf energy gained from eating sheep

[JackAtOmenApps]

Implementing the already existing class attribute that was correctly used in Sheep, but not in Wolf.

[github-actions]

Performance benchmarks:

Model	Size	Init time [95% CI]	Run time [95% CI]
Schelling	small	🔵 +1.3% [+1.2%, +1.5%]	🔵 -0.0% [-0.2%, +0.1%]
Schelling	large	🔵 +11.4% [-12.9%, +51.6%]	🔵 -0.4% [-0.8%, +0.0%]
WolfSheep	small	🔵 +1.0% [+0.7%, +1.3%]	🔵 +1.8% [+0.5%, +3.0%]
WolfSheep	large	🔴 +24.1% [+6.5%, +47.2%]	🔵 +2.4% [+0.7%, +3.9%]
BoidFlockers	small	🔵 +0.5% [-0.0%, +1.1%]	🔵 -0.3% [-1.1%, +0.4%]
BoidFlockers	large	🔵 +1.2% [+0.9%, +1.6%]	🔵 -1.0% [-1.4%, -0.5%]

[rht]

Merged, thank you.

[EwoutH]

Good catch, thanks!