chore: delete unused and duplicate function, it exists under /utils (#4657)

extensions/default/src/utils/_shared/getNextSRSeriesNumber.ts

@@ -1,10 +0,0 @@
-const MIN_SR_SERIES_NUMBER = 4700;
-
-export default function getNextSRSeriesNumber(displaySetService) {
-  const activeDisplaySets = displaySetService.getActiveDisplaySets();
-  const srDisplaySets = activeDisplaySets.filter(ds => ds.Modality === 'SR');
-  const srSeriesNumbers = srDisplaySets.map(ds => ds.SeriesNumber);
-  const maxSeriesNumber = Math.max(...srSeriesNumbers, MIN_SR_SERIES_NUMBER);
-
-  return maxSeriesNumber + 1;
-}