cuda backend

Signed-off-by: AdityaPandeyCN <adityapand3y666@gmail.com>

Author: AdityaPandeyCN

benchmarks/PSOGlobalOptimization/pso_global_optimizers.jmd

@@ -27,14 +27,15 @@ using OptimizationMetaheuristics, OptimizationSciPy
 using ParallelParticleSwarms
 using ForwardDiff
 using KernelAbstractions
+using CUDA
 using StaticArrays, LinearAlgebra
 
 const PSOKernel     = ParallelParticleSwarms.ParallelPSOKernel
 const SyncPSOKernel = ParallelParticleSwarms.ParallelSyncPSOKernel
 const SerPSO        = ParallelParticleSwarms.SerialPSO
 const HPso          = ParallelParticleSwarms.HybridPSO
 
-const BACKEND = CPU()  # use CUDABackend() from CUDA.jl on GPU CI
+const BACKEND = CUDABackend()
 ```
 
 ```julia