Hotfix: Fix energy call of isochoric neo-hookean

[miguelmaso]

See title

[github-actions]

Benchmark Results (Julia v1)

Time benchmarks

	main	4ba91d0...	main / 4ba91d0...
Constitutive models/Visco-elastic Ψ	0.0536 ± 0.033 ms	0.0543 ± 0.033 ms	0.987 ± 0.87
Constitutive models/Visco-elastic ∂Ψu	0.0593 ± 0.0024 ms	0.0603 ± 0.0026 ms	0.984 ± 0.059
Constitutive models/Visco-elastic ∂Ψuu	0.109 ± 0.02 ms	0.111 ± 0.018 ms	0.982 ± 0.24
Simulations/StaticMechanicalDirichlet	0.139 ± 0.014 s	0.142 ± 0.011 s	0.977 ± 0.12
Simulations/StaticMechanicalNeumann	0.125 ± 0.016 s	0.137 ± 0.015 s	0.912 ± 0.15
Simulations/ViscoElastic	20.3 s	20.3 s	1
Tensor algebra/Cofactor	0.07 ± 0 μs	0.07 ± 0.01 μs	1 ± 0.14
Tensor algebra/Det(A)Inv(A')	0.111 ± 0.01 μs	0.12 ± 0.01 μs	0.925 ± 0.11
Tensor algebra/δδ_λ_2d	30 ± 0 ns	30 ± 0 ns	1 ± 0
Tensor algebra/δδ_μ_2d	30 ± 0 ns	30 ± 0 ns	1 ± 0
time_to_load	2.89 ± 0.027 s	3.07 ± 0.042 s	0.941 ± 0.016

Memory benchmarks

	main	4ba91d0...	main / 4ba91d0...
Constitutive models/Visco-elastic Ψ	1.24 k allocs: 0.0777 MB	1.24 k allocs: 0.0777 MB	1
Constitutive models/Visco-elastic ∂Ψu	1.29 k allocs: 0.0826 MB	1.29 k allocs: 0.0826 MB	1
Constitutive models/Visco-elastic ∂Ψuu	2.25 k allocs: 0.149 MB	2.25 k allocs: 0.149 MB	1
Simulations/StaticMechanicalDirichlet	1.51 M allocs: 0.108 GB	1.51 M allocs: 0.108 GB	1
Simulations/StaticMechanicalNeumann	1.48 M allocs: 0.0927 GB	1.48 M allocs: 0.0927 GB	1
Simulations/ViscoElastic	0.327 G allocs: 20.6 GB	0.327 G allocs: 20.6 GB	1
Tensor algebra/Cofactor	1 allocs: 0.0781 kB	1 allocs: 0.0781 kB	1
Tensor algebra/Det(A)Inv(A')	4 allocs: 0.25 kB	4 allocs: 0.25 kB	1
Tensor algebra/δδ_λ_2d	0 allocs: 0 B	0 allocs: 0 B
Tensor algebra/δδ_μ_2d	0 allocs: 0 B	0 allocs: 0 B
time_to_load	0.149 k allocs: 11.1 kB	0.159 k allocs: 11.6 kB	0.964