chore: migrate from ncc (CJS) to rollup (ESM)

Switch bundler from @vercel/ncc to rollup to support ESM-only
@actions/toolkit v3 packages. This upgrades all @actions/* dependencies
to their latest major versions and adds "type": "module" to package.json.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -3,6 +3,7 @@
   "description": "mise tool setup action",
   "version": "4.0.1",
   "author": "jdx",
+  "type": "module",
   "private": true,
   "repository": {
     "type": "git",
@@ -22,7 +23,7 @@
     "format:check": "prettier --check **/*.ts",
     "format:write": "prettier --write **/*.ts",
     "lint": "npx eslint . && npm run format:check",
-    "package": "ncc build -s src/index.ts --license licenses.txt",
+    "package": "npx rimraf ./dist && npx rollup --config rollup.config.ts --configPlugin @rollup/plugin-typescript",
     "package:watch": "npm run package -- --watch",
     "version": "./scripts/version.sh",
     "prepare": "husky"
@@ -30,24 +31,30 @@
   "license": "MIT",
   "dependencies": {
     "@actions/cache": "^4.0.0",
-    "@actions/core": "^1.11.1",
-    "@actions/exec": "^1.1.1",
-    "@actions/glob": "^0.5.0",
+    "@actions/core": "^3.0.0",
+    "@actions/exec": "^3.0.0",
+    "@actions/glob": "^0.6.0",
+    "@actions/io": "^3.0.0",
     "@types/handlebars": "^4.0.40",
     "handlebars": "^4.7.8"
   },
   "devDependencies": {
     "@eslint/eslintrc": "^3.2.0",
     "@eslint/js": "^10.0.0",
+    "@rollup/plugin-commonjs": "^29.0.0",
+    "@rollup/plugin-json": "^6.1.0",
+    "@rollup/plugin-node-resolve": "^16.0.0",
+    "@rollup/plugin-typescript": "^12.0.0",
     "@types/eslint__js": "^8.42.3",
     "@types/node": "^24",
-    "@vercel/ncc": "^0.38.3",
     "eslint": "^10.0.0",
     "globals": "^17.0.0",
     "husky": "^9.1.7",
     "jest": "^30",
     "js-yaml": "^4.1.0",
     "prettier": "^3.4.1",
+    "rimraf": "^6.0.0",
+    "rollup": "^4.0.0",
     "typescript": "^5.7.2",
     "typescript-eslint": "^8.16.0"
   }

rollup.config.ts

@@ -0,0 +1,22 @@
+import commonjs from '@rollup/plugin-commonjs'
+import json from '@rollup/plugin-json'
+import nodeResolve from '@rollup/plugin-node-resolve'
+import typescript from '@rollup/plugin-typescript'
+
+const config = {
+  input: 'src/index.ts',
+  output: {
+    esModule: true,
+    file: 'dist/index.js',
+    format: 'es',
+    sourcemap: true
+  },
+  plugins: [
+    typescript(),
+    nodeResolve({ preferBuiltins: true }),
+    commonjs(),
+    json()
+  ]
+}
+
+export default config

tsconfig.json

@@ -13,7 +13,9 @@
     "forceConsistentCasingInFileNames": true,
     "strict": true,
     "skipLibCheck": true,
-    "newLine": "lf"
+    "newLine": "lf",
+    "isolatedModules": true,
+    "allowSyntheticDefaultImports": true
   },
   "exclude": ["./dist", "./node_modules", "./__tests__", "./coverage"]
 }