ci: fix webpack 5 enabling for tests (#21436)

* ci: fix webpack 5 enabling for tests

* refactor: move default location

* Disable incompatible suite

.github/workflows/build_test_deploy.yml

@@ -160,7 +160,7 @@ jobs:
       NEXT_TELEMETRY_DISABLED: 1
       NEXT_TEST_JOB: 1
       HEADLESS: true
-      NEXT_WEBPACK5: 1
+      NEXT_PRIVATE_TEST_WEBPACK5_MODE: 1
 
     steps:
       - uses: actions/checkout@v2
@@ -174,7 +174,7 @@ jobs:
       - run: yarn install --check-files
         if: ${{ steps.docs-change.outputs.DOCS_CHANGE != 'docs-only' }}
 
-      - run: xvfb-run node run-tests.js test/integration/{link-ref,production,basic,async-modules,font-optimization,ssr-ctx,worker-loader}/test/index.test.js test/acceptance/*.test.js
+      - run: xvfb-run node run-tests.js test/integration/{link-ref,production,basic,async-modules,font-optimization,ssr-ctx}/test/index.test.js test/acceptance/*.test.js
         if: ${{ steps.docs-change.outputs.DOCS_CHANGE != 'docs-only' }}
 
   testLegacyReact:

packages/next/build/webpack-config.ts

@@ -204,11 +204,7 @@ export default async function getBaseWebpackConfig(
     rewrites: Rewrite[]
   }
 ): Promise<webpack.Configuration> {
-  initWebpack(
-    config.future?.webpack5 ||
-      (config.future?.webpack5 !== false &&
-        Number(process.env.NEXT_WEBPACK5) > 0)
-  )
+  initWebpack(!!config.future?.webpack5)
 
   let plugins: PluginMetaData[] = []
   let babelPresetPlugins: { dir: string; config: any }[] = []

packages/next/next-server/server/config.ts

@@ -91,7 +91,7 @@ const defaultConfig: NextConfig = {
   future: {
     strictPostcssConfiguration: false,
     excludeDefaultMomentLocales: false,
-    webpack5: false,
+    webpack5: Number(process.env.NEXT_PRIVATE_TEST_WEBPACK5_MODE) > 0,
   },
   serverRuntimeConfig: {},
   publicRuntimeConfig: {},