gh-84116: Add missing backslash to _SubParsersAction.add_parser signature
#182046
| Job | Run time |
|---|---|
| 15s | |
| 13s | |
| 5m 26s | |
| 1m 44s | |
| 1m 52s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 0s | |
| 2s | |
| 9m 32s |