Fix TypeError in meshgrid (#8252)

Fixes #8251

Remove `indexing="ij"` will not affect anything since it's default
behavior in torch.

### Types of changes
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Non-breaking change (fix or new feature that would not break
existing functionality).
- [ ] Breaking change (fix or new feature that would cause existing
functionality to change).
- [ ] New tests added to cover the changes.
- [ ] Integration tests passed locally by running `./runtests.sh -f -u
--net --coverage`.
- [ ] Quick tests passed locally by running `./runtests.sh --quick
--unittests --disttests`.
- [ ] In-line docstrings updated.
- [ ] Documentation updated, tested `make html` command in the `docs/`
folder.

---------

Signed-off-by: YunLiu <[email protected]>

monai/networks/blocks/pos_embed_utils.py

@@ -56,7 +56,7 @@ def build_sincos_position_embedding(
         grid_h = torch.arange(h, dtype=torch.float32)
         grid_w = torch.arange(w, dtype=torch.float32)
 
-        grid_h, grid_w = torch.meshgrid(grid_h, grid_w, indexing="ij")
+        grid_h, grid_w = torch.meshgrid(grid_h, grid_w)
 
         if embed_dim % 4 != 0:
             raise AssertionError("Embed dimension must be divisible by 4 for 2D sin-cos position embedding")
@@ -75,7 +75,7 @@ def build_sincos_position_embedding(
         grid_w = torch.arange(w, dtype=torch.float32)
         grid_d = torch.arange(d, dtype=torch.float32)
 
-        grid_h, grid_w, grid_d = torch.meshgrid(grid_h, grid_w, grid_d, indexing="ij")
+        grid_h, grid_w, grid_d = torch.meshgrid(grid_h, grid_w, grid_d)
 
         if embed_dim % 6 != 0:
             raise AssertionError("Embed dimension must be divisible by 6 for 3D sin-cos position embedding")