Update google/auth/crypt/rsa.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: daniel-sanche

google/auth/crypt/rsa.py

@@ -102,7 +102,7 @@ def __init__(self, private_key, key_id=None):
         elif module_str.startswith(CRYPTOGRAPHY_KEY_MODULE_PREFIX):
             impl_lib = _cryptography_rsa
         else:
-            raise ValueError(f"unrecognized private key type: {private_key}")
+            raise ValueError(f"unrecognized private key type: {type(private_key)}")
         self._impl = impl_lib.RSASigner(private_key, key_id=key_id)
 
     @property  # type: ignore