@actions/cache: convert to an ESM module (#2275)

* `@actions/cache`: convert to an ESM module

* Update the fixture to ESM syntax

* Update the cache workflows

* Bump `@actions/glob` to `0.6.1`

* Fix awaiting in the cache unit tests

* Fix a type issues in contracts

* Export the `DownloadOptions`/`UploadOptions` like before

* More cache test fixes

* Make the cache units tests better

* Add some more logging

* Add retries to restore-cache.mjs

packages/cache/__tests__/__fixtures__/index.js

@@ -1,8 +1,9 @@
 // Certain env variables are not set by default in a shell context and are only available in a node context from a running action
 // In order to be able to restore and save cache e2e in a shell when running CI tests, we need these env variables set
-const fs = require('fs');
-const os = require('os');
-const filePath = process.env[`GITHUB_ENV`]
+import fs from 'fs'
+import os from 'os'
+
+const filePath = process.env['GITHUB_ENV']
 fs.appendFileSync(filePath, `ACTIONS_CACHE_SERVICE_V2=true${os.EOL}`, {
     encoding: 'utf8'
 })