r2plus1d_18 segfault on linux gpu CI jobs

[NicolasHug]

test_models.py segfaults on r2plus1d_18_cuda on the unittest_linux_gpu_py3.8 CI job. See e.g. failures in #3700 or #3699

cc @seemethere

[fmassa]

Interesting, worth investigating more closely, as this might be an issue with some of the pytorch kernels that are used to run this model on GPU (or the machine is running out of memory)

[NicolasHug]

Another report of the same issue: #3765

[vfdev-5]

@NicolasHug I tried that locally and could not reproduce it with 2-3 executions. I also think it should hide other failures with few other tests that are broken locally on my infra. Maybe, it worth also disable it before suggesting a fix.

[fmassa]

I think the segfaults might be due to memory issues, but to be safe let's disable it for now