CUDA Linker test: remove unneeded @require_context
CUDA Linker test: remove unneeded @require_context

Tests that operate through the normal APIs (e.g. `@cuda.jit`) don't need
to have a prior context available.

seibert/numba,cpcloud/numba,IntelLabs/numba,numba/numba,IntelLabs/numba,IntelLabs/numba,cpcloud/numba,numba/numba,seibert/numba,cpcloud/numba,seibert/numba,numba/numba,IntelLabs/numba,seibert/numba,numba/numba,cpcloud/numba,IntelLabs/numba,seibert/numba,cpcloud/numba,numba/numba