Enable alwaysStrict for build scripts (#152778)

Turns on `alwaysStrict` and removes `'use strict';` from our `.ts` files

build/linux/rpm/dependencies-generator.ts

@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import { spawnSync } from 'child_process';
 import { constants, statSync } from 'fs';
 import path = require('path');