fix: only update 2.15 for content redaction rule TAL events

Revert 2.14 change — new event types should only be added to the latest
API spec version (2.15).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: thibault-intercom

descriptions/2.14/api.intercom.io.yaml

@@ -14246,9 +14246,6 @@ components:
           - conversation_topic_change
           - conversation_topic_creation
           - conversation_topic_deletion
-          - content_redaction_rule_creation
-          - content_redaction_rule_deletion
-          - content_redaction_rule_update
           - custom_authentication_token_creation
           - help_center_settings_change
           - inbound_conversations_change