feat(python/robomp): implemented has_authorized_impl_event in the

- Implement `has_authorized_impl_event` in the database to retrieve historical authorization state.
- Update `_enforce_impl_authorization` to permit actions if prior events on the issue provided implementation authorization.
- Normalize maintainer logins by stripping `[bot]` suffixes and allow match-regex to ignore them.

python/robomp/src/config.py

@@ -305,7 +305,10 @@ class Settings(BaseSettings):
 
     @property
     def maintainer_logins(self) -> frozenset[str]:
-        items = [piece.strip().lstrip("@").lower() for piece in self.maintainer_logins_raw.split(",")]
+        items = [
+            piece.strip().lstrip("@").lower().removesuffix("[bot]")
+            for piece in self.maintainer_logins_raw.split(",")
+        ]
         return frozenset(item for item in items if item)
 
     def allows(self, full_name: str) -> bool: