- Also buildignore the postgresql*-implementation symbols: this is
needed in order to bootstrap when no postgresql version curretnly
has valid symbols provided. Once the packages are built, OBS
could translate this to the pgname-* packages and accept the
ignores; during bootstrap though, there is nothing providing the
symbol and the existing buildignores do not suffice.

I think this is the bits and pieces we are missing for Staging:E

In the past we did not run into this as a new postgresql version was first introduced, and only in a 2nd step the default switched.
This meant we had already packages in the tree that matched expectations... but in fact bootstrap woyuld not work.