Upgrade to typescript-eslint v6 (#25904)

app/javascript/mastodon/utils/filters.ts

@@ -7,7 +7,7 @@ export const toServerSideType = (columnType: string) => {
     case 'account':
       return columnType;
     default:
-      if (columnType.indexOf('list:') > -1) {
+      if (columnType.includes('list:')) {
         return 'home';
       } else {
         return 'public'; // community, account, hashtag

app/javascript/mastodon/utils/numbers.ts

@@ -55,7 +55,7 @@ export function toShortNumber(sourceNumber: number): ShortNumber {
  */
 export function pluralReady(
   sourceNumber: number,
-  division: DecimalUnits,
+  division: DecimalUnits | null,
 ): number {
   if (division == null || division < DECIMAL_UNITS.HUNDRED) {
     return sourceNumber;