CI: Add nvmath-python integration tests to nightly CI

[leofang]

The nvmath-python team suggests to run their sample tests.

[leofang]

@carterbox could you determine which code samples we should cover? We certainly don't want to run nvmath.device samples (which are run elsewhere)?

[carterbox]

We certainly don't want to run nvmath.device samples (which are run elsewhere)?

Why? Where are they already run?

[carterbox]

Except for the device examples, the tests should autoskip if the required dependencies are not installed.

pytest tests/example_tests/fft_tests/ tests/example_tests/matmul_tests/ tests/example_tests/solver_tests/ tests/example_tests/sparse_tests/ tests/example_tests/tensor_tests/ tests/example_tests/distributed_tests/

Installing mpi4py/cupy/torch/numba will increase the number of tests that run from 10s of tests up to 350 tests.

NOTE: UST tests use numba to compile host code.