Fix: Disable Sparse Decompression for Dense Compressors (#237)

* Turn off sparse decompression when sparse compressor is dense

* Update: Condiition to use enum instead of raw string

* Remove unnecesarry style change

src/compressed_tensors/compressors/model_compressors/model_compressor.py

@@ -310,7 +310,10 @@ def decompress(self, model_path: str, model: Module):
         model_path = get_safetensors_folder(model_path)
         sparse_decompressed = False
 
-        if self.sparsity_compressor is not None:
+        if (
+            self.sparsity_compressor is not None
+            and self.sparsity_config.format != CompressionFormat.dense.value
+        ):
             # Sparse decompression is applied on the model_path
             dense_gen = self.sparsity_compressor.decompress(model_path)
             self._replace_weights(dense_gen, model)