remove sha256 as it's already available in the digest (#420)

Author: samhita-alla

ollama/_client.py

@@ -554,7 +554,7 @@ def create_blob(self, path: Union[str, Path]) -> str:
     digest = f'sha256:{sha256sum.hexdigest()}'
 
     with open(path, 'rb') as r:
-      self._request_raw('POST', f'/api/blobs/sha256:{digest}', content=r)
+      self._request_raw('POST', f'/api/blobs/{digest}', content=r)
 
     return digest