Handling Orphaned Transactions from Superseded DeclareMiningJob Requests

[NonsoAmadi10]

When a DeclareMiningJob request (Job A) is received and processed, the transactions associated with this job are stored in the mempool. If there are missing transactions, a ProvideMissingTransactions request is sent. However, if a new DeclareMiningJob request (Job B) arrives before the missing transactions for Job A are provided, the transactions for Job A that were recognized are correctly eliminated, but the transactions for Job A that are provided later are still added to the mempool. These transactions belong to a job that has already been superseded and thus will never be removed, leading to orphaned transactions in the mempool.

#868 (comment)