@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__/save-cache.mjs

@@ -0,0 +1,24 @@
+#!/usr/bin/env node
+// Helper script to save cache for e2e testing
+import * as cache from '../lib/cache.js'
+
+const [prefix, runId] = process.argv.slice(2)
+
+if (!prefix || !runId) {
+  console.error('Usage: save-cache.mjs <prefix> <runId>')
+  process.exit(1)
+}
+
+const key = `test-${prefix}-${runId}`
+const paths = ['test-cache', '~/test-cache']
+
+console.log(`Saving cache with key: ${key}`)
+console.log(`Paths: ${paths.join(', ')}`)
+
+try {
+  const cacheId = await cache.saveCache(paths, key)
+  console.log(`Cache saved with ID: ${cacheId}`)
+} catch (error) {
+  console.error('Error saving cache:', error)
+  process.exit(1)
+}