message: doc: add release note for fee field deprecation
diff: @@ -108,6 +108,15 @@ Updated RPCs
  causes the lock to be written persistently to the wallet database. This
  allows UTXOs to remain locked even after node restarts or crashes. (#23065)
  +- The top-level fee fields `fee`, `modifiedfee`, `ancestorfees` and `descendantfees`
  + returned by RPCs `getmempoolentry`,`getrawmempool(verbose=true)`,
  + `getmempoolancestors(verbose=true)` and `getmempooldescendants(verbose=true)`
  + are deprecated and will be removed in the next major version (use
  + `-deprecated=fees` if needed in this version). The same fee fields can be accessed
  + through the `fees` object in the result. WARNING: deprecated
  + fields `ancestorfees` and `descendantfees` are denominated in sats, whereas all
  + fields in the `fees` object are denominated in BTC. (#22689)
  +
  New RPCs
  --------
  