Remove GPU context creation lock

PerfectNumbers.Core/Gpu/MersenneNumberOrderGpuTester.cs

@@ -10,7 +10,6 @@ public class MersenneNumberOrderGpuTester(GpuKernelType kernelType, bool useGpuO
         public void Scan(ulong exponent, UInt128 twoP, LastDigit lastDigit, UInt128 maxK, ref bool isPrime)
         {
                 var gpuLease = GpuKernelPool.GetKernel(_useGpuOrder);
-                var execution = gpuLease.EnterExecutionScope();
                 var accelerator = gpuLease.Accelerator;
                 var stream = gpuLease.Stream;
                 int batchSize = GpuConstants.ScanBatchSize; // large batch improves GPU occupancy and avoids TDR
@@ -61,7 +60,6 @@ public class MersenneNumberOrderGpuTester(GpuKernelType kernelType, bool useGpuO
                 }
 
                 foundBuffer.Dispose();
-                execution.Dispose();
                 gpuLease.Dispose();
         }
 }