Stable sqrt

[miguelmaso]

• Using sqrt from Gridap and removed custom implementation
• Required the latest version of Gridap (v0.19.8), where sqrt definition has been included

[github-actions]

Benchmark Results (Julia v1)

Time benchmarks

	main	ad7309b...	main / ad7309b...
Constitutive models/Visco-elastic Ψ	0.0475 ± 0.032 ms	0.0486 ± 0.034 ms	0.979 ± 0.96
Constitutive models/Visco-elastic ∂Ψu	0.0623 ± 0.0021 ms	0.055 ± 0.002 ms	1.13 ± 0.055
Constitutive models/Visco-elastic ∂Ψuu	0.11 ± 0.014 ms	0.103 ± 0.016 ms	1.07 ± 0.21
Simulations/StaticMechanicalDirichlet	0.139 ± 0.0084 s	0.136 ± 0.008 s	1.02 ± 0.086
Simulations/StaticMechanicalNeumann	0.129 ± 0.013 s	0.131 ± 0.011 s	0.986 ± 0.13
Simulations/ViscoElastic	21.1 s	18.7 s	1.13
Tensor algebra/Cofactor	0.07 ± 0.01 μs	0.07 ± 0.01 μs	1 ± 0.2
Tensor algebra/Det(A)Inv(A')	0.13 ± 0.001 μs	0.13 ± 0.01 μs	1 ± 0.077
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	2.55 ± 0.011 s	2.87 ± 0.14 s	0.889 ± 0.042

Memory benchmarks

	main	ad7309b...	main / ad7309b...
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	1.36 k allocs: 0.0898 MB	1.29 k allocs: 0.0824 MB	1.09
Constitutive models/Visco-elastic ∂Ψuu	2.32 k allocs: 0.155 MB	2.24 k allocs: 0.148 MB	1.05
Simulations/StaticMechanicalDirichlet	1.51 M allocs: 0.109 GB	1.51 M allocs: 0.109 GB	1
Simulations/StaticMechanicalNeumann	1.48 M allocs: 0.0933 GB	1.48 M allocs: 0.0933 GB	1
Simulations/ViscoElastic	0.343 G allocs: 22 GB	0.325 G allocs: 20.3 GB	1.09
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	0.149 k allocs: 11.1 kB	1