Fix string retrieval to cope with cppyy changes for LCG_106b (!79603) · Merge requests · atlas / athena

Two fixes:

Fix string retrieval to cope with cppyy changes for LCG_106b.
- The cppyy version was updated from 1.6.X to 3.1.X, which is a major change. So, the code needs to call as_string() on that object.
Remove DataHeader loading from SG
- Trying to load 'StoreGateSvc+EventSelector' produces an ERROR since 24.0.79:
```
SGInputLoader  ERROR    obj  ( 'DataHeader' , 'StoreGateSvc+EventSelector' )  has no provider, and is only Transient
```
- We can just delete this line. It is not needed to have this transformation running.

This changes are needed so the EventIndex Producer runs on the Tier0 using the latest 24.0 versions

Fix string retrieval to cope with cppyy changes for LCG_106b