feat(discord): Add feature flag for metric alerts (#57034)

Create feature flag for Discord metric alerts

src/sentry/conf/server.py

@@ -1537,6 +1537,8 @@ SENTRY_FEATURES = {
     "organizations:integrations-stacktrace-link": False,
     # Allow orgs to create a Discord integration
     "organizations:integrations-discord": False,
+    # Enable Discord metric alert notifications
+    "organizations:integrations-discord-metric-alerts": False,
     # Enable Discord integration notifications
     "organizations:integrations-discord-notifications": False,
     # Enable Opsgenie integration

src/sentry/features/__init__.py

@@ -84,6 +84,7 @@ default_manager.add("organizations:higher-ownership-limit", OrganizationFeature,
 default_manager.add("organizations:invite-members", OrganizationFeature, FeatureHandlerStrategy.INTERNAL)
 default_manager.add("organizations:invite-members-rate-limits", OrganizationFeature, FeatureHandlerStrategy.INTERNAL)
 default_manager.add("organizations:integrations-discord", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
+default_manager.add("organizations:integrations-discord-metric-alerts", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
 default_manager.add("organizations:integrations-discord-notifications", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
 default_manager.add("organizations:integrations-opsgenie-migration", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
 default_manager.add("organizations:integrations-open-pr-comment", OrganizationFeature, FeatureHandlerStrategy.REMOTE)