fix(alerts): Only grab anomalies if the detection type matches (#76738)

We were always getting anomalies if the flag was on, but we only need to
check this if the alert itself is using the dynamic detection type.

src/sentry/incidents/subscription_processor.py

@@ -518,7 +518,11 @@ def process_update(self, subscription_update: QuerySubscriptionUpdate) -> None:
  "organizations:fake-anomaly-detection", self.subscription.project.organization
  )
 
- if self.has_anomaly_detection:
+ potential_anomalies = None
+ if (
+ self.has_anomaly_detection
+ and self.alert_rule.detection_type == AlertRuleDetectionType.DYNAMIC
+ ):
  potential_anomalies = self.get_anomaly_data_from_seer(aggregation_value)
  if potential_anomalies is None:
  return []
@@ -545,8 +549,7 @@ def process_update(self, subscription_update: QuerySubscriptionUpdate) -> None:
  with transaction.atomic(router.db_for_write(AlertRule)):
  # Triggers is the threshold - NOT an instance of a trigger
  for trigger in self.triggers:
- detection_type = trigger.alert_rule.detection_type
- if self.has_anomaly_detection and detection_type == AlertRuleDetectionType.DYNAMIC:
+ if potential_anomalies:
  # NOTE: There should only be one anomaly in the list
  for potential_anomaly in potential_anomalies:
  # check to see if we have enough data for the dynamic alert rule now
@@ -565,7 +568,7 @@ def process_update(self, subscription_update: QuerySubscriptionUpdate) -> None:
  ) and not self.check_trigger_matches_status(trigger, TriggerStatus.ACTIVE):
  metrics.incr(
  "incidents.alert_rules.threshold.alert",
- tags={"detection_type": detection_type},
+ tags={"detection_type": self.alert_rule.detection_type},
  )
  incident_trigger = self.trigger_alert_threshold(
  trigger, aggregation_value
@@ -584,7 +587,7 @@ def process_update(self, subscription_update: QuerySubscriptionUpdate) -> None:
  ):
  metrics.incr(
  "incidents.alert_rules.threshold.resolve",
- tags={"detection_type": detection_type},
+ tags={"detection_type": self.alert_rule.detection_type},
  )
  incident_trigger = self.trigger_resolve_threshold(
  trigger, aggregation_value
@@ -602,7 +605,7 @@ def process_update(self, subscription_update: QuerySubscriptionUpdate) -> None:
  # And the trigger is not yet active
  metrics.incr(
  "incidents.alert_rules.threshold.alert",
- tags={"detection_type": detection_type},
+ tags={"detection_type": self.alert_rule.detection_type},
  )
  # triggering a threshold will create an incident and set the status to active
  incident_trigger = self.trigger_alert_threshold(trigger, aggregation_value)
@@ -620,7 +623,7 @@ def process_update(self, subscription_update: QuerySubscriptionUpdate) -> None:
  ):
  metrics.incr(
  "incidents.alert_rules.threshold.resolve",
- tags={"detection_type": detection_type},
+ tags={"detection_type": self.alert_rule.detection_type},
  )
  incident_trigger = self.trigger_resolve_threshold(
  trigger, aggregation_value