Only load vite6 and rollup4 if they're used

Author: timfish

packages/integration-tests/tsconfig.json

@@ -4,6 +4,7 @@
   "include": ["./**/*"],
   "compilerOptions": {
     "esModuleInterop": true,
+    "skipLibCheck": true,
     "types": ["node", "jest"]
   }
 }

packages/integration-tests/utils/create-cjs-bundles.ts

@@ -1,8 +1,6 @@
 import * as vite from "vite";
-import * as vite6 from "vite6";
 import * as path from "path";
 import * as rollup from "rollup";
-import * as rollup4 from "rollup4";
 import { default as webpack4 } from "webpack4";
 import { webpack as webpack5 } from "webpack5";
 import * as esbuild from "esbuild";
@@ -40,7 +38,8 @@ export function createCjsBundles(
     });
   }
 
-  if (plugins.length === 0 || plugins.includes("vite6")) {
+  if (NODE_MAJOR_VERSION >= 18 && plugins.length === 0 || plugins.includes("vite6")) {
+    const vite6 = require("vite6");
     void vite6.build({
       clearScreen: false,
       build: {
@@ -75,6 +74,7 @@ export function createCjsBundles(
   }
 
   if ((NODE_MAJOR_VERSION >= 18 && plugins.length === 0) || plugins.includes("rollup4")) {
+    const rollup4 = require("rollup4");
     void rollup4
       .rollup({
         input: entrypoints,