gh-143200: fix UAFs in Element.__{set,get}item__ when the element is concurrently mutated
#101894
| Job | Run time |
|---|---|
| 40s | |
| 40s |
Element.__{set,get}item__ when the element is concurrently mutated
#101894
| Job | Run time |
|---|---|
| 40s | |
| 40s |