python SDKError __str__ bug

[syvokobylka]

Attempt to represent python SDKError object as a string leads to another exception happening

.....
except looker_sdk.error.SDKError as ex:
    logger.error(f"Some important data and {str(ex)}")

Call stack:
2024-07-04 11:35:58.130
TypeError: sequence item 0: expected str instance, ErrorDetail found
2024-07-04 11:35:58.130
{sep.join(self.errors)}
2024-07-04 11:35:58.130
File "/root/.pyenv/versions/3.10.5/lib/python3.10/site-packages/looker_sdk/error.py", line 85, in str

[jeremytchang]

Closing as fixed. #1486