fix: Resolve issue with x-linode-cli-rows extension (#510)

## 📝 Description

This change resolves an issue that caused the `x-linode-cli-rows` spec
extension to not work as expected, which caused the `linodes
backups-list {instanceId}` to be unusable.

## ✔️ How to Test

Fixed command:
```bash
linode-cli linodes backups-list 12345
```

Integration tests:
```bash
make RUN_LONG_TESTS=TRUE testint
```

Author: lgarber-akamai

linodecli/baked/response.py

@@ -187,13 +187,14 @@ def __init__(self, response):
             )
         else:
             self.attrs = _parse_response_model(response.schema)
-        self.rows = response.schema.extensions.get("linode-cli-rows")
+        self.rows = response.extensions.get("linode-cli-rows")
         self.nested_list = response.extensions.get("linode-cli-nested-list")
 
     def fix_json(self, json):
         """
         Formats JSON from the API into a list of rows
         """
+
         if self.rows:
             return self._fix_json_rows(json)
         if self.nested_list: