Upgrade Rollup to v4

Upgrade Rollup from v2 to v4 and move the CommonJS and ESM build options into the npm build script. Remove the unused browser build and configuration file, and avoid installing development dependencies in the artifact-based test jobs.

Author: TrySound

.github/workflows/ci.yml

@@ -55,9 +55,6 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
 
-      - name: Install dependencies
-        run: npm install --ignore-scripts
-
       - name: Download build
         uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:

package.json

@@ -34,13 +34,13 @@
     "node": ">=0.10.0"
   },
   "scripts": {
-    "build": "rollup -c",
+    "build": "rollup is-plain-object.js --format cjs --file dist/is-plain-object.js && rollup is-plain-object.js --format esm --file dist/is-plain-object.mjs",
     "test": "node test.js",
-    "prepare": "rollup -c"
+    "prepare": "npm run build"
   },
   "devDependencies": {
     "gulp-format-md": "^1.0.0",
-    "rollup": "^2.22.1"
+    "rollup": "^4.62.5"
   },
   "keywords": [
     "check",