Add missing int cast (#3062)

Summary:
Fixes #3061

Pull Request resolved: #3062

Reviewed By: saitcakmak

Differential Revision: D85436183

Pulled By: Balandat

fbshipit-source-id: a493ad00d57a9f8722537e48d2e5487a1938af15

Author: AdrianSosic

botorch/sampling/base.py

@@ -60,7 +60,9 @@ def __init__(
                 f"got {sample_shape}."
             )
         self.sample_shape = sample_shape
-        self.seed = seed if seed is not None else torch.randint(0, 1000000, (1,)).item()
+        self.seed = (
+            seed if seed is not None else int(torch.randint(0, 1000000, (1,)).item())
+        )
         self.register_buffer("base_samples", None)
 
     @abstractmethod