private void removeStaticMember(ConsumerGroupMember oldMember) {
        if (oldMember.instanceId() != null) {
            staticMembers.remove(oldMember.instanceId());
        }
    }
Remove the static member mapping if the removed member is static.

@param oldMember The member to remove.
group-coordinator/src/main/java/org/apache/kafka/coordinator/group/modern/consumer/ConsumerGroup.java