Convert CommonJS to ESM modules (#100)

* Initial plan

* Convert CommonJS to ESM imports

Co-authored-by: dawidd6 <[email protected]>

* Fix: Use namespace imports for built-in modules and standardize quotes

Co-authored-by: dawidd6 <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: dawidd6 <[email protected]>

Author: Copilot

main.js

@@ -1,10 +1,10 @@
-const core = require("@actions/core")
-const exec = require("@actions/exec")
-const io = require('@actions/io')
-const firstline = require("firstline")
-const path = require("path")
-const fs = require("fs")
-const os = require('os');
+import * as core from "@actions/core"
+import * as exec from "@actions/exec"
+import * as io from "@actions/io"
+import firstline from "firstline"
+import * as path from "path"
+import * as fs from "fs"
+import * as os from "os"
 
 // Map CPU architectures to qemu-user-static package suffixes
 const hostArchMap = {

package.json

@@ -1,5 +1,6 @@
 {
   "name": "action-debian-package",
+  "type": "module",
   "dependencies": {
     "@actions/core": "^3.0.0",
     "@actions/exec": "^3.0.0",

post.js

@@ -1,5 +1,5 @@
-const core = require("@actions/core")
-const exec = require("@actions/exec")
+import * as core from "@actions/core"
+import * as exec from "@actions/exec"
 
 async function main() {
     try {