Migrate to ESM and upgrade dependencies (#1574)

* Migrate to ESM

* updated package.json version

* Update README for v6 and clean up dev dependencies

* Remove unused ts-node

* fix audit issue

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Co-authored-by: gowridurgad <gowridurgad@gmail.com>

src/cache-restore.ts

@@ -5,13 +5,13 @@ import path from 'path';
 import fs from 'fs';
 import os from 'os';
 
-import {State} from './constants';
+import {State} from './constants.js';
 import {
   getCacheDirectories,
   getPackageManagerInfo,
   repoHasYarnBerryManagedDependencies,
   PackageManagerInfo
-} from './cache-utils';
+} from './cache-utils.js';
 
 export const restoreCache = async (
   packageManager: string,