next: gt4py stencil cache concurrency error during pytest -n

[muellch]

Currently in icon4py pytest -n to speed up testing might result in an error since the gt4py_cache will get accessed by multiple processes at the same time.

Was reproduced with the following command:

pytest -n 4 -v --datatest -k "test_nonhydro_predictor_step or test_nonhydro_corrector_step" --backend=gtfn_cpu model/atmosphere/dycore/tests/dycore_tests/test_solve_nonhydro.py