Deleted the constant SKIP_CUDA_TEST_WITH_DML (#24113)
### Description
Deleted the constant SKIP_CUDA_TEST_WITH_DML. It does not seem to be
used anywhere.
### Motivation and Context
The constant SKIP_CUDA_TEST_WITH_DML prohibits onnxruntime to be
compiled when both of the flags -use_cuda and -use_dml are set.
Co-authored-by: Andreas Hussing <ahu@visiopharm.com>
