Merge bitcoin/bitcoin#23416: doc: Remove fee delta TODO from txmempool.cpp

fa32cc0 doc: Remove fee delta TODO from txmempool.cpp (MarcoFalke)

Pull request description:

  This refactor request was added in commit eb30666, though it didn't explain why the refactor is needed and what the goal is. Given that this wasn't touched for more than 5 years, it doesn't seem critical. Generally, non-trivial `TODO`s make more sense as GitHub issues, so that they can be discussed and triaged more easily.

ACKs for top commit:
  laanwj:
    Code review ACK fa32cc0

Tree-SHA512: 6629fef543e815136c82c38aa8ba2c4de68a5fe94c6954f2559e468f7e59052e02dd7c221d3b159be0314eaf0dbb18f74814297c58f76e2289c47e8d4f49be4e

Author: laanwj

src/txmempool.cpp

@@ -481,8 +481,6 @@ void CTxMemPool::addUnchecked(const CTxMemPoolEntry &entry, setEntries &setAnces
     indexed_transaction_set::iterator newit = mapTx.insert(entry).first;
 
     // Update transaction for any feeDelta created by PrioritiseTransaction
-    // TODO: refactor so that the fee delta is calculated before inserting
-    // into mapTx.
     CAmount delta{0};
     ApplyDelta(entry.GetTx().GetHash(), delta);
     if (delta) {