Fix dtype in fix_dim_of_size_1

Author: ValerianRey

src/torchjd/sparse/_structured_sparse_tensor.py

@@ -268,7 +268,7 @@ def get_full_source(source: list[int], destination: list[int], ndim: int) -> lis
 
 
 def fix_dim_of_size_1(physical: Tensor, strides: Tensor) -> tuple[Tensor, Tensor]:
-    is_of_size_1 = torch.tensor([s == 1 for s in physical.shape])
+    is_of_size_1 = torch.tensor([s == 1 for s in physical.shape], dtype=torch.bool)
     return physical.squeeze(), strides[:, ~is_of_size_1]