Dim fix for sparsemodels (x2)

Author: I8dNLo

fastembed/common/model_description.py

@@ -52,9 +52,9 @@ def __init__(
         sources: ModelSource,
         model_file: str,
         description: str,
-        dim: Optional[int],
         license: str,
         size_in_GB: float,
+        dim: Optional[int] = None,
         additional_files: Optional[List[str]] = None,
         tasks: Optional[Dict[str, int]] = None,
         vocab_size: int,