fix: structured metadata not always passed down for processing deletes (#15526)

Signed-off-by: Edward Welch <edward.welch@grafana.com>
(cherry picked from commit a3808b6)

Author: slim-bean

pkg/logql/log/metrics_extraction.go

@@ -283,7 +283,7 @@ func (sp *filteringStreamExtractor) Process(ts int64, line []byte, structuredMet
 		}
 	}
 
-	return sp.extractor.Process(ts, line)
+	return sp.extractor.Process(ts, line, structuredMetadata...)
 }
 
 func (sp *filteringStreamExtractor) ProcessString(ts int64, line string, structuredMetadata ...labels.Label) (float64, LabelsResult, bool) {