build: add sideEffects: false flags

packages/compiler/package.json

@@ -5,6 +5,7 @@
   "main": "index.js",
   "module": "dist/compiler.esm-bundler.js",
   "typings": "dist/index.d.ts",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/vuejs/vue.git"

packages/core/package.json

@@ -5,6 +5,7 @@
   "main": "index.js",
   "module": "dist/core.esm-bundler.js",
   "typings": "dist/index.d.ts",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/vuejs/vue.git"

packages/observer/package.json

@@ -6,6 +6,7 @@
   "module": "dist/observer.esm-bundler.js",
   "typings": "dist/index.d.ts",
   "unpkg": "dist/observer.global.js",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/vuejs/vue.git"

packages/renderer-dom/package.json

@@ -6,6 +6,7 @@
   "module": "dist/renderer-dom.esm-bundler.js",
   "typings": "dist/index.d.ts",
   "unpkg": "dist/renderer-dom.global.js",
+  "sideEffects": false,
   "buildOptions": {
     "name": "VueDOMRenderer",
     "formats": ["esm", "cjs", "global", "esm-browser"]

packages/scheduler/package.json

@@ -5,6 +5,7 @@
   "main": "index.js",
   "module": "dist/scheduler.esm-bundler.js",
   "typings": "dist/index.d.ts",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/vuejs/vue.git"

packages/vue/package.json

@@ -6,6 +6,7 @@
   "module": "dist/vue.esm-bundler.js",
   "typings": "dist/index.d.ts",
   "unpkg": "dist/vue.global.js",
+  "sideEffects": false,
   "buildOptions": {
     "name": "Vue",
     "compat": true,