update CHANGELOG.md

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## v24.20
 
 ### Pre-releases
+- `v24.20-alpha6`
 - `v24.20-alpha5`
 - `v24.20-alpha4`
 - `v24.20-alpha3`
@@ -13,6 +14,7 @@
 - Default password criteria are more restrictive (#372, `v24.20-alpha1`, Compatible with Seacat Auth Webui v24.19-alpha and later, Seacat Account Webui v24.08-beta and later)
 
 ### Fix
+- Delete client cookie on introspection failure (#385, `v24.20-alpha6`)
 - Extend session expiration at cookie entrypoint (#383, `v24.20-alpha5`)
 - Do not log failed LDAP login as error (#381, `v24.20-alpha4`)
 - Properly handle Argon2 verification error in login call (#378, `v24.20-alpha3`)