DEV: Delete en-SG moment-locale (#11220)

This is now in the lowercase en-sg file, and it causes issues on macOS dev environments to have both en-SG and en-sg files in the same location.

vendor/assets/javascripts/moment-locale/en-SG.js

@@ -1,66 +0,0 @@
-//! moment.js locale configuration
-
-;(function (global, factory) {
-   typeof exports === 'object' && typeof module !== 'undefined'
-       && typeof require === 'function' ? factory(require('../moment')) :
-   typeof define === 'function' && define.amd ? define(['../moment'], factory) :
-   factory(global.moment)
-}(this, (function (moment) { 'use strict';
-
-
-    var enSG = moment.defineLocale('en-SG', {
-        months : 'January_February_March_April_May_June_July_August_September_October_November_December'.split('_'),
-        monthsShort : 'Jan_Feb_Mar_Apr_May_Jun_Jul_Aug_Sep_Oct_Nov_Dec'.split('_'),
-        weekdays : 'Sunday_Monday_Tuesday_Wednesday_Thursday_Friday_Saturday'.split('_'),
-        weekdaysShort : 'Sun_Mon_Tue_Wed_Thu_Fri_Sat'.split('_'),
-        weekdaysMin : 'Su_Mo_Tu_We_Th_Fr_Sa'.split('_'),
-        longDateFormat : {
-            LT : 'HH:mm',
-            LTS : 'HH:mm:ss',
-            L : 'DD/MM/YYYY',
-            LL : 'D MMMM YYYY',
-            LLL : 'D MMMM YYYY HH:mm',
-            LLLL : 'dddd, D MMMM YYYY HH:mm'
-        },
-        calendar : {
-            sameDay : '[Today at] LT',
-            nextDay : '[Tomorrow at] LT',
-            nextWeek : 'dddd [at] LT',
-            lastDay : '[Yesterday at] LT',
-            lastWeek : '[Last] dddd [at] LT',
-            sameElse : 'L'
-        },
-        relativeTime : {
-            future : 'in %s',
-            past : '%s ago',
-            s : 'a few seconds',
-            ss : '%d seconds',
-            m : 'a minute',
-            mm : '%d minutes',
-            h : 'an hour',
-            hh : '%d hours',
-            d : 'a day',
-            dd : '%d days',
-            M : 'a month',
-            MM : '%d months',
-            y : 'a year',
-            yy : '%d years'
-        },
-        dayOfMonthOrdinalParse: /\d{1,2}(st|nd|rd|th)/,
-        ordinal : function (number) {
-            var b = number % 10,
-                output = (~~(number % 100 / 10) === 1) ? 'th' :
-                (b === 1) ? 'st' :
-                (b === 2) ? 'nd' :
-                (b === 3) ? 'rd' : 'th';
-            return number + output;
-        },
-        week : {
-            dow : 1, // Monday is the first day of the week.
-            doy : 4  // The week that contains Jan 4th is the first week of the year.
-        }
-    });
-
-    return enSG;
-
-})));