feat: adding greater_equal Scalar variant (#91324)
Fixes https://github.com/pytorch/functorch/issues/1080
```py
import torch
from functorch import vmap
def f(x):
return torch.greater_equal(torch.cumsum(x, dim=0), .5 * 10)
x = torch.randn([10,10])
vmap(f)(x)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/91324
Approved by: https://github.com/zou3519
