Release notes for getdeploymentinfo rpc

doc/release-notes-23508.md

@@ -0,0 +1,9 @@
+Updated RPCs
+------------
+
+- Information on soft fork status has been moved from `getblockchaininfo`
+  to `getdeploymentinfo` which allows querying soft fork status at any
+  block, rather than just at the chain tip. Inclusion of soft fork
+  status in `getblockchaininfo` can currently be restored using the
+  configuration `-deprecatedrpc=softforks`, but this will be removed in
+  a future release. (#23508)