[autorevert] Filter out disabled workflows in workflow resolver (#7617)

Autorevert had trouble dispatching `inductor` workflow. Turns out, we
have an old deleted workflow with the same name:
https://github.com/pytorch/pytorch/actions/workflows/inductor-cu126.yml

The short term fix (this PR) is to filter out disabled workflows from
the cache, and warn about naming conflicts.


### Testing

```
python -m pytorch_auto_revert  autorevert-checker inductor --hours 18 --hud-html --as-of "2025-12-22 23:25:05"
```

Successfully dispatched workflow inductor for commit
270863426366da61609430dffb479a452311d02b (run:
https://github.com/pytorch/pytorch/actions/workflows/inductor.yml?query=branch%3Atrunk%2F270863426366da61609430dffb479a452311d02b


Successfully dispatched workflow inductor for commit
9be4f54558636a68d068b40d424c1bf129f17f59 (run:
https://github.com/pytorch/pytorch/actions/workflows/inductor.yml?query=branch%3Atrunk%2F9be4f54558636a68d068b40d424c1bf129f17f59)

Author: izaitsevfb

aws/lambda/pytorch-auto-revert/pytorch_auto_revert/workflow_resolver.py

@@ -110,12 +110,26 @@ def _build_indices(self) -> None:
         for attempt in RetryWithBackoff():
             with attempt:
                 for w in self._repository.get_workflows():
+                    # Skip disabled workflows (deleted files may leave stale entries)
+                    state = getattr(w, "state", "") or ""
+                    if state != "active":
+                        continue
                     name = getattr(w, "name", "") or ""
                     path = getattr(w, "path", "") or ""
                     base = os.path.basename(path) if path else ""
                     if not (name and base):
                         continue
                     ref = WorkflowRef(display_name=name, file_name=base)
+                    if name in self._by_display:
+                        existing = self._by_display[name]
+                        logging.warning(
+                            "Duplicate workflow display name '%s': %s vs %s, keeping %s",
+                            name,
+                            existing.file_name,
+                            base,
+                            existing.file_name,
+                        )
+                        continue
                     self._by_display[name] = ref
                     self._by_file[base] = ref