TorchSharp memory issue

```
m = torch.nn.Conv2d(3, 64, 7, 2, 3, bias=False).cuda()

for i in range(1000000):
x = torch.randn(1, 3, 224, 224, dtype=torch.float).cuda()
y = m.forward(x)
```
```
var m=TorchSharp.torch.nn.Conv2d(3, 64, 7, 2, 3, bias: false).cuda();

for (int i = 0; i < 1000000; i++)
{
var x = torch.randn(1, 3, 224, 224).@float().cuda();
var y = m.forward(x);
}
```
In PyTorch, when using GPU inference, GPU memory can be released at the appropriate time. In TorchSharp, when using GPU inference, there is a GPU memory leak that requires manual release.