Remove unneeded comment

Signed-off-by: Jon Kartago Lamida <[email protected]>

pkg/streamingpromql/operators/functions/rate_increase.go

@@ -74,11 +74,6 @@ func rate(isCounter, isRate bool) RangeVectorStepFunction {
 	}
 }
 
-// histogramRate is utility function for rate/increase/delta.
-// It calculates the rate (allowing for counter resets if isCounter is true for rate and increase),
-// extrapolates if the first/last sample is close to the boundary, and returns
-// the result as either per-second (if isRate is true) or overall (this is increase function).
-// If isCounter and isRate are both false, this function will calculate the delta.
 func histogramRate(isCounter, isRate bool, hCount int, hHead []promql.HPoint, hTail []promql.HPoint, rangeStart int64, rangeEnd int64, rangeSeconds float64, emitAnnotation types.EmitAnnotationFunc) (*histogram.FloatHistogram, error) {
 	firstPoint := hHead[0]
 	hHead = hHead[1:]