ci: point version bumps to the correct python folder (#138)

Currently, we cannot create a new release due to the error:
`FileNotFoundError: File not found: 'python/Cargo.toml'`

This PR fixes the issue by pointing to the correct Python folder.

Author: ChunxuTang

.bumpversion.toml

@@ -34,7 +34,7 @@ search = 'version = "{current_version}"'
 replace = 'version = "{new_version}"'
 
 [[tool.bumpversion.files]]
-filename = "python/Cargo.toml"
+filename = "crates/lance-graph-python/Cargo.toml"
 search = 'version = "{current_version}"'
 replace = 'version = "{new_version}"'