[BUG] TestFem.test_integrate_gradient_cpu segfaults on arm64 macOS runner

[shi-eric]

Bug Description

https://github.com/NVIDIA/warp/actions/runs/11832532560/job/32970493971 was the first workflow that started failing. By running the tests serially, we see that there's something about test_integrate_gradient_cpu that is problematic on the macos-latest runner provided by GitHub, which happens to be an arm64 runner. The problem seems to be avoided if we switch to an x86_64 runner by using the macos-13 tag...

test_grid_2d_cpu (warp.tests.test_fem.TestFem.test_grid_2d_cpu) ...
test_grid_2d_cpu (warp.tests.test_fem.TestFem.test_grid_2d_cpu) ... ok
test_grid_3d_cpu (warp.tests.test_fem.TestFem.test_grid_3d_cpu) ...
test_grid_3d_cpu (warp.tests.test_fem.TestFem.test_grid_3d_cpu) ... ok
test_hex_mesh_cpu (warp.tests.test_fem.TestFem.test_hex_mesh_cpu) ...
test_hex_mesh_cpu (warp.tests.test_fem.TestFem.test_hex_mesh_cpu) ... ok
test_implicit_fields (warp.tests.test_fem.TestFem.test_implicit_fields) ...
test_implicit_fields (warp.tests.test_fem.TestFem.test_implicit_fields) ... ok
test_integrate_gradient_cpu (warp.tests.test_fem.TestFem.test_integrate_gradient_cpu) ...
/Users/runner/work/_temp/ac229663-9565-4bb4-bb78-954bc9168419.sh: line 1:  3798 Segmentation fault: 11  python -m warp.tests --junit-report-xml rspec.xml --coverage --coverage-xml 

System Information

No response