fix(snuba): add missing api.metrics.totals.second_query to Referrer enum (#104155)

Fixing this particular issue:

```
Traceback (most recent call last):
  File "/usr/src/sentry/src/sentry/snuba/referrer.py", line 964, in validate_referrer
    raise Exception(error_message)
Exception: referrer api.metrics.totals.second_query is not part of Referrer Enum
```

Closes
https://linear.app/getsentry/issue/TET-1522/snuba-queries-raising-warning

Author: constantinius

src/sentry/snuba/referrer.py

@@ -419,6 +419,9 @@ class Referrer(StrEnum):
     API_ISSUES_RELATED_ISSUES = "api.issues.related_issues"
     API_METRICS_TOTALS = "api.metrics.totals"
     API_METRICS_TOTALS_INITIAL_QUERY = "api.metrics.totals.initial_query"
+    API_METRICS_TOTALS_SECOND_QUERY = "api.metrics.totals.second_query"
+    API_METRICS_SERIES_SECOND_QUERY = "api.metrics.series.second_query"
+
     API_ORGANIZATION_TRACE_ITEM_DETAILS = "api.organization-trace-item-details"
     API_ORGANIZATION_EVENT_STATS_FIND_TOPN = "api.organization-event-stats.find-topn"
     API_ORGANIZATION_EVENT_STATS_METRICS_ENHANCED = "api.organization-event-stats.metrics-enhanced"