[DOCS] RELEASE-NOTES.md (squash) v1.21.4-0 security

Refs: https://codeberg.org/forgejo/forgejo/issues/2158
(cherry picked from commit 7e663e496e212ec4f27f8808c441ab583d48c9ad)
(cherry picked from commit 3e5d45a2ab1a98f14c53f5aa36bb164ce6d7a3aa)
(cherry picked from commit 6c22e906fbaffc4451020e113b5ca2d890f1cf67)

Author: earl-warren

RELEASE-NOTES.md

@@ -29,8 +29,7 @@ This stable release includes security and bug fixes as well as documentation imp
 
 * Security fixes
 
-  * [Update github.com/cloudflare/circl](https://codeberg.org/forgejo/forgejo/commit/82ec85550e8604725e98c30e2d0f884db7514018)
-  * [Require token for GET subscription endpoint](https://codeberg.org/forgejo/forgejo/commit/0841fb63a198b416a66268d8104daa4299d40107)
+  * [Require token for GET subscription endpoint](https://codeberg.org/forgejo/forgejo/commit/6a66e8c7486b0be873dfc55dfdef9ba056970a90)
 
 * Bug fixes