Cancel concurrent CI

[miguelmaso]

When there is an open PR with active actions working on, and more commits are pushed, there can be redundant compilations and testing.

This PR avoids redundant workflow runs.

[github-actions]

Benchmark Results (Julia v1)

Time benchmarks

	main	797fce6...	main / 797fce6...
Constitutive models/Visco-elastic Ψ	0.0497 ± 0.021 ms	0.0535 ± 0.022 ms	0.928 ± 0.54
Constitutive models/Visco-elastic ∂Ψu	0.062 ± 0.0096 ms	0.0614 ± 0.0051 ms	1.01 ± 0.18
Constitutive models/Visco-elastic ∂Ψuu	0.109 ± 0.021 ms	0.109 ± 0.038 ms	0.998 ± 0.4
Simulations/StaticMechanicalDirichlet	0.23 ± 0.0084 s	0.231 ± 0.012 s	0.993 ± 0.062
Simulations/StaticMechanicalNeumann	0.247 ± 0.012 s	0.246 ± 0.0041 s	1.01 ± 0.05
Simulations/ViscoElastic	0.0525 h	0.053 h	0.991
Tensor algebra/δδ_λ_2d	19 ± 1 ns	18 ± 1 ns	1.06 ± 0.081
Tensor algebra/δδ_μ_2d	19 ± 1 ns	19 ± 1 ns	1 ± 0.074
time_to_load	2.28 ± 0.016 s	2.3 ± 0.017 s	0.99 ± 0.01

Memory benchmarks

	main	797fce6...	main / 797fce6...
Constitutive models/Visco-elastic Ψ	1.24 k allocs: 0.0782 MB	1.24 k allocs: 0.0782 MB	1
Constitutive models/Visco-elastic ∂Ψu	1.36 k allocs: 0.0904 MB	1.36 k allocs: 0.0904 MB	1
Constitutive models/Visco-elastic ∂Ψuu	2.31 k allocs: 0.155 MB	2.31 k allocs: 0.155 MB	1
Simulations/StaticMechanicalDirichlet	1.69 M allocs: 0.118 GB	1.69 M allocs: 0.118 GB	1
Simulations/StaticMechanicalNeumann	2.19 M allocs: 0.14 GB	2.19 M allocs: 0.14 GB	1
Simulations/ViscoElastic	2.72 G allocs: 192 GB	2.72 G allocs: 192 GB	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