fix: add pref.ai_guardrail_sensitivity audit action

Clears the Audit-job schema break (Unknown action detected -
pref.ai_guardrail_sensitivity, ApiTest.getActions_detectingNewOnes)
that has been red since verify run 35940430459 and persisted into the
2026-09-25 nightly 36075881928. Additive constant in WorkspaceOrOrg,
matching the existing pref_* = "pref.*" convention. Compile-verified
(slack-api-client BUILD SUCCESS). Does not address the Remote-job
environmental flakes (SCIM2 _ed suffix, slacklists, files NPE).

❤️

Author: zimeg

slack-api-client/src/main/java/com/slack/api/audit/Actions.java

@@ -342,6 +342,7 @@ private WorkspaceOrOrg() {
         public static final String pref_show_join_leave_welcome_party_changed = "pref.show_join_leave_welcome_party_changed";
         public static final String pref_allow_native_giphy_gif_picker = "pref.allow_native_giphy_gif_picker";
         public static final String pref_ai_feature_default_access_changed = "pref.ai_feature_default_access_changed";
+        public static final String pref_ai_guardrail_sensitivity = "pref.ai_guardrail_sensitivity";
         public static final String pref_allow_workflow_export = "pref.allow_workflow_export";
         public static final String pref_alt_text_reminders = "pref.alt_text_reminders";
         public static final String pref_canvas_printing_enabled = "pref.canvas_printing_enabled";