Convert to ESM.

Context: https://github.com/actions/typescript-action/pull/969

__fixtures__/cache.ts

@@ -0,0 +1,7 @@
+import * as cache from '@actions/cache'
+import { jest } from '@jest/globals'
+
+export const ReserveCacheError = cache.ReserveCacheError
+export const restoreCache = jest.fn<typeof cache.restoreCache>()
+export const saveCache = jest.fn<typeof cache.saveCache>()
+export const ValidationError = cache.ValidationError

__fixtures__/core.ts

@@ -0,0 +1,13 @@
+import type * as core from '@actions/core'
+import { jest } from '@jest/globals'
+
+export const debug = jest.fn<typeof core.debug>()
+export const error = jest.fn<typeof core.error>()
+export const exportVariable = jest.fn<typeof core.exportVariable>()
+export const getInput = jest.fn<typeof core.getInput>()
+export const getState = jest.fn<typeof core.getState>()
+export const info = jest.fn<typeof core.info>()
+export const saveState = jest.fn<typeof core.saveState>()
+export const setFailed = jest.fn<typeof core.setFailed>()
+export const setOutput = jest.fn<typeof core.setOutput>()
+export const warning = jest.fn<typeof core.warning>()

__fixtures__/github.ts

@@ -0,0 +1,15 @@
+import * as github from '@actions/github'
+import { jest } from '@jest/globals'
+
+export const context = {
+  repo: {
+    owner: 'test-owner',
+    repo: 'test-repo'
+  },
+  sha: 'test-sha',
+  ref: 'test-ref',
+  workflow: 'test-workflow',
+  job: 'test-job',
+  runId: '12345'
+}
+export const getOctokit = jest.fn<typeof github.getOctokit>()

__fixtures__/glob.ts

@@ -0,0 +1,4 @@
+import * as glob from '@actions/glob'
+import { jest } from '@jest/globals'
+
+export const create = jest.fn<typeof glob.create>()