Gauss3d distributed tests

[msimberg]

Requires #1004 and the gauss3d test data.

Enables the gauss3d experiment as test input for the distributed tests.

[github-actions]

Mandatory Tests

Please make sure you run these tests via comment before you merge!

• cscs-ci run default

Optional Tests

To run benchmarks you can use:

• cscs-ci run benchmark-bencher

To run tests and benchmarks with the DaCe backend you can use:

• cscs-ci run dace

To run tests with MPI you can use:

• cscs-ci run distributed

To run test levels ignored by the default test suite (mostly simple datatest for static fields computations) you can use:

• cscs-ci run extra

For more detailed information please look at CI in the EXCLAIM universe.