@actions/core: convert to ESM module

packages/core/src/core.ts

@@ -1,11 +1,11 @@
-import {issue, issueCommand} from './command'
-import {issueFileCommand, prepareKeyValueMessage} from './file-command'
-import {toCommandProperties, toCommandValue} from './utils'
+import {issue, issueCommand} from './command.js'
+import {issueFileCommand, prepareKeyValueMessage} from './file-command.js'
+import {toCommandProperties, toCommandValue} from './utils.js'
 
 import * as os from 'os'
 import * as path from 'path'
 
-import {OidcClient} from './oidc-utils'
+import {OidcClient} from './oidc-utils.js'
 
 /**
  * Interface for getInput options
@@ -400,19 +400,19 @@ export async function getIDToken(aud?: string): Promise<string> {
 /**
  * Summary exports
  */
-export {summary} from './summary'
+export {summary} from './summary.js'
 
 /**
  * @deprecated use core.summary
  */
-export {markdownSummary} from './summary'
+export {markdownSummary} from './summary.js'
 
 /**
  * Path exports
  */
-export {toPosixPath, toWin32Path, toPlatformPath} from './path-utils'
+export {toPosixPath, toWin32Path, toPlatformPath} from './path-utils.js'
 
 /**
  * Platform utilities exports
  */
-export * as platform from './platform'
+export * as platform from './platform.js'