@actions/exec: convert to ESM module

jest.config.js

@@ -5,7 +5,13 @@ module.exports = {
   testEnvironment: 'node',
   testMatch: ['**/__tests__/*.test.ts'],
   moduleNameMapper: {
-    '^(\\.{1,2}/.*)\\.js$': '$1'
+    '^(\\.{1,2}/.*)\\.js$': '$1',
+    '^@actions/io$': '<rootDir>/packages/io/lib/io.js',
+    '^@actions/io/lib/io-util$': '<rootDir>/packages/io/lib/io-util.js',
+    '^@actions/http-client$': '<rootDir>/packages/http-client/lib/index.js',
+    '^@actions/http-client/lib/auth$': '<rootDir>/packages/http-client/lib/auth.js',
+    '^@actions/github$': '<rootDir>/packages/github/lib/github.js',
+    '^@actions/github/lib/utils$': '<rootDir>/packages/github/lib/utils.js'
   },
   transform: {
     '^.+\\.(ts|js)$': ['ts-jest', {
@@ -13,12 +19,14 @@ module.exports = {
       diagnostics: {warnOnly: true},
       tsconfig: {
         allowJs: true,
-        esModuleInterop: true
+        esModuleInterop: true,
+        module: 'commonjs',
+        moduleResolution: 'node'
       }
     }]
   },
   transformIgnorePatterns: [
-    '/node_modules/(?!(@octokit|universal-user-agent|before-after-hook)/)'
+    '/node_modules/(?!(@octokit|@actions/github|@actions/http-client|@actions/io|universal-user-agent|before-after-hook)/)'
   ],
   verbose: true
 }