If an entry-point has a missing dependency then all the entry-points
that would have pointed to that dependency are also removed from
the dependency graph.
Previously we were still processing the dependencies of an entry-point
even if it had already been removed from the graph because it depended
upon a missing dependency that had previously been removed due to another
entry-point depending upon it.
This caused the dependency processing to crash rather than gracefully
logging and handling the missing invalid entry-point.
Fixes#29624
PR Close#30270