The forgetChild() method must call super

Summary

Context

Description of change

Migration guide

Timeline

References

Summary

A recent global key duplication detection refactor now requires
Element subclasses that override the forgetChild() to call super().

Context

When encountering a global key duplication that will be
cleaned up by an element rebuild later,
we must not report global key duplication.
Our previous implementation threw an error as soon as
duplication was detected, and didn’t wait for the rebuild if the
element with the duplicated global key would have rebuilt.