revert slots

Author: Kludex

instrumentation/opentelemetry-instrumentation-urllib3/src/opentelemetry/instrumentation/urllib3/__init__.py

@@ -146,10 +146,12 @@ def response_hook(
 _excluded_urls_from_env = get_excluded_urls("URLLIB3")
 
 
-@dataclass(slots=True)
+@dataclass
 class RequestInfo:
     """Arguments that were passed to the ``urlopen()`` call."""
 
+    __slots__ = ("method", "url", "headers", "body")
+
     # The type annotations here come from ``HTTPConnectionPool.urlopen()``.
     method: str
     url: str