fix(hc): Avoid redundantly resolving to RegionCategory enum object (#52571)

src/sentry/types/region.py

@@ -131,7 +131,10 @@ def _parse_config(region_config: Any) -> Iterable[Region]:
         if isinstance(config_value, Region):
             yield config_value
         else:
-            config_value["category"] = RegionCategory[config_value["category"]]  # type: ignore
+            category = config_value["category"]  # type: ignore[unreachable]
+            config_value["category"] = (
+                category if isinstance(category, RegionCategory) else RegionCategory[category]
+            )
             yield Region(**config_value)