Merge bitcoin/bitcoin#33013: [29.x] Backport #32521

f25dc84b28 doc: update release notes for 29.x (Antoine Poinsot)
313023369b qa: functional test a transaction running into the legacy sigop limit (Antoine Poinsot)
0a4671d5eb qa: unit test standardness of inputs packed with legacy sigops (Antoine Poinsot)
204b965915 policy: make pathological transactions packed with legacy sigops non-standard. (Antoine Poinsot)

Pull request description:

  This backports PR #32521 to make the change available to miners who can't (or don't want to) upgrade past version 29.

ACKs for top commit:
  marcofleon:
    reACK f25dc84b28
  glozow:
    ACK f25dc84b28

Tree-SHA512: d5e06618720ed1a96d8a5fccdd8d1dbcbb5748505aa0df69198326828fe13f220e55bbce813f6f2daae82d23348e1f83a3a20a28639ec3fc2455c5b6e79a56e6

doc/release-notes.md

@@ -37,6 +37,17 @@ unsupported systems.
 Notable changes
 ===============
 
+### Mempool Policy
+
+- The maximum number of potentially executed legacy signature operations in a
+  single standard transaction is now limited to 2500. Signature operations in all
+  previous output scripts, in all input scripts, as well as all P2SH redeem
+  scripts (if there are any) are counted toward the limit. The new limit is
+  assumed to not affect any known typically formed standard transactions. The
+  change was done to prepare for a possible BIP54 deployment in the future.
+
+- #32521 policy: make pathological transactions packed with legacy sigops non-standard
+
 ### Updated Settings
 
 - The `-maxmempool` and `-dbcache` startup parameters are now capped on
@@ -132,11 +143,11 @@ Credits
 Thanks to everyone who directly contributed to this release:
 
 - achow101
+- Antoine Poinsot
 - benthecarman
 - bigspider
 - Brandon Odiwuor
 - brunoerg
-- darosior
 - davidgumberg
 - dergoegge
 - enirox001