Merge branch 'docs-policy-alerts-tier' into 'master'

Fix to tier for Policy Alerts

See merge request gitlab-org/gitlab!54846

doc/user/application_security/threat_monitoring/index.md

@@ -186,7 +186,7 @@ There are two ways to create policy alerts:
 Once added, the UI updates and displays a warning about the dangers of too many alerts.
-#### Enable or disable Policy Alerts **(FREE SELF)**
+#### Enable or disable Policy Alerts **(ULTIMATE)**
 Policy Alerts is under development but ready for production use.
 It is deployed behind a feature flag that is **enabled by default**.