fix NaN(s) error in SH tests

[aelligp]

This tries to fix the constant errors on both GPU and CPU CI for shearheating. The tests pass both locally and if re-run on the CI.

Shearheating3D: Error During Test at /var/lib/buildkite-agent/builds/amdgpu1-luraess-com/julialang/justrelax-dot-jl/test/test_shearheating3D.jl:239
  Got exception outside of a @test
  NaN(s)

Current solution to the problem:

try
    iters, thermal = Shearheating3D(igg; nx=nx, ny=ny, nz=nz)
catch e
    @warn e
    try
       iters, thermal = Shearheating3D(igg; nx=nx, ny=ny, nz=nz)
    catch e2
       @warn e2
    end
 end

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Additional details and impacted files

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