Remove redundant Date ctor utility function

This helper can be replaced with the plain
`Date` constructor.

app/assets/javascripts/lib/utils/datetime_utility.js

@@ -883,21 +883,6 @@ export const approximateDuration = (seconds = 0) => {
   return n__('1 day', '%d days', seconds < ONE_DAY_LIMIT ? 1 : days);
 };
 
-/**
- * A utility function which helps creating a date object
- * for a specific date. Accepts the year, month and day
- * returning a date object for the given params.
- *
- * @param {Int} year the full year as a number i.e. 2020
- * @param {Int} month the month index i.e. January => 0
- * @param {Int} day the day as a number i.e. 23
- *
- * @return {Date} the date object from the params
- */
-export const dateFromParams = (year, month, day) => {
-  return new Date(year, month, day);
-};
-
 /**
  * A utility function which computes the difference in seconds
  * between 2 dates.

ee/app/assets/javascripts/analytics/merge_request_analytics/utils.js

 import dateFormat from 'dateformat';
 import {
   getMonthNames,
-  dateFromParams,
   getDateInPast,
   getDayDifference,
   secondsToDays,
@@ -32,8 +31,8 @@ export const computeMonthRangeData = (startDate, endDate, format = dateFormats.i
     const monthIndex = dateCursor.getMonth();
     const year = dateCursor.getFullYear();
 
-    const mergedAfter = dateFromParams(year, monthIndex, 1);
-    const mergedBefore = dateFromParams(year, monthIndex + 1, 1);
+    const mergedAfter = new Date(year, monthIndex, 1);
+    const mergedBefore = new Date(year, monthIndex + 1, 1);
 
     monthData.unshift({
       year,

spec/frontend/lib/utils/datetime_utility_spec.js

@@ -889,17 +889,6 @@ describe('localTimeAgo', () => {
   });
 });
 
-describe('dateFromParams', () => {
-  it('returns the expected date object', () => {
-    const expectedDate = new Date('2019-07-17T00:00:00.000Z');
-    const date = datetimeUtility.dateFromParams(2019, 6, 17);
-
-    expect(date.getYear()).toBe(expectedDate.getYear());
-    expect(date.getMonth()).toBe(expectedDate.getMonth());
-    expect(date.getDate()).toBe(expectedDate.getDate());
-  });
-});
-
 describe('differenceInSeconds', () => {
   const startDateTime = new Date('2019-07-17T00:00:00.000Z');