chore(deps): update dependency eslint to v9 (#362)

* chore(deps): update dependency eslint to v9

* chore: migrate flat config

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: MURAKAMI Masahiko <fossamagna2@gmail.com>

.github/workflows/test.yml

@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [16.x, 18.x, 20.x]
+        node-version: [18.x, 20.x]
         # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
 
     steps:
@@ -28,6 +28,7 @@ jobs:
         cache: 'npm'
     - run: npm ci
     - run: npm run build --if-present
+    - run: npm run lint
     - run: npm test
     - name: Coveralls GitHub Action
       uses: coverallsapp/github-action@v2.2.3

eslint.config.js

@@ -0,0 +1,14 @@
+const js = require("@eslint/js");
+const globals = require("globals");
+
+module.exports = [
+  js.configs.recommended,
+  {
+    languageOptions: {
+      globals: {
+        ...globals.node,
+        ...globals.commonjs,
+      },
+    },
+  },
+];