Run dynamo/test_dynamic_shapes serially (#92215)
Per my findings in https://github.com/pytorch/pytorch/issues/92196#issuecomment-1383029544
> The test itself dynamo/test_dynamic_shapes is not flaky and all passes when I try to run it locally. However, this test is set to run in parallel with other tests on the runner (2 tests at a times). After many tries, I can only reproduce the issue once when dynamo/test_dynamic_shapes is run in parallel with test_comparison_utils
After many retries, I could reproduce the issue once locally when running (https://paste.sh/_mFImq6V#FgbKq6IQBg65PKUFA08Ah_Vb)
```
python test/run_test.py --verbose --exclude-jit-executor --exclude-distributed-tests -i test_comparison_utils dynamo/test_dynamic_shapes
```
So setting this test to run serially to avoid further flakiness while the root cause is investigated.
Here are some example flaky failures:
* https://github.com/pytorch/pytorch/issues/92196
* https://github.com/pytorch/pytorch/issues/92178
* https://github.com/pytorch/pytorch/issues/92042
* https://github.com/pytorch/pytorch/issues/92210
The test takes 30s or so to finish, so its duration is not a concern.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/92215
Approved by: https://github.com/clee2000
