Merge identical forks (#5405)
Consider these requirements from pylint 3.2.5:
```
Requires-Dist: dill >=0.3.6 ; python_version >= "3.11"
Requires-Dist: dill >=0.3.7 ; python_version >= "3.12"
```
We will split on the python version, but then we may pick a version of
`dill` that's `>=0.3.7` in both branches and also have an otherwise
identical resolution in both forks. In this case, we merge both forks
and store only their conjoined markers.