Merge bitcoin/bitcoin#30493: policy: enable full-rbf by default

590456e3f1 policy: enable full-rbf by default (Peter Todd)
195e98ea8e doc: add release notes for full-rbf (Peter Todd)

Pull request description:

  This pull request enables full rbf (mempool policy) by default. #28132 was closed recently with this [comment](https://github.com/bitcoin/bitcoin/pull/28132#issuecomment-2225369634).

  ---

  Rationale:

  - Full RBF config option was added in July 2022: https://github.com/bitcoin/bitcoin/pull/25353

  - It is used regularly: https://mempool.space/rbf#fullrbf

  - Most mining pools are using it: https://github.com/bitcoin/bitcoin/pull/28132#issuecomment-2059120917

ACKs for top commit:
  petertodd:
    ACK 590456e3f1
  instagibbs:
    reACK 590456e3f1
  glozow:
    reACK 590456e3f1
  achow101:
    ACK 590456e3f1
  ariard:
    tested ACK 590456e3
  murchandamus:
    reACK 590456e3f1

Tree-SHA512: 83fceef9961021687e6ff979041f89be0c616f7a49cc28a5d7edf7d8ad064fcb9c0e2af0c31f4f89867a9f6dff4e40ef8ad4dbd624e7d6a4e00ac1f1c1f66c7a

doc/release-notes-30493.md

@@ -0,0 +1,4 @@
+Full Replace-By-Fee
+===================
+
+`mempoolfullrbf=1` is now set by default.