Update to Yarn 3 (#13140)

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
           YARN_ENABLE_SCRIPTS: false # disable post-install scripts
           YARN_NODE_LINKER: pnp # use pnp linker for better linking performance: it's meant to update yarn cache only
         run: |
-          yarn install --immutable --skip-builds
+          yarn install --mode=skip-build
 
   yarn-validate:
     name: Validate Yarn dependencies and constraints
@@ -327,6 +327,10 @@ jobs:
           "
       - name: Install
         run: yarn install
+        env:
+          # The "Support self-references on old Node.js" step mutates the
+          # package.json file, causing a yarn.lock update.
+          YARN_ENABLE_IMMUTABLE_INSTALLS: false
       - uses: actions/download-artifact@v2
         with:
           name: babel-artifact
@@ -344,7 +348,7 @@ jobs:
         with:
           node-version: 10
       - name: Test Node.js 10
-        run: yarn test:runtime:node
+        run: node test/runtime-integration/node.cjs
       - name: Use Node.js 12.0
         uses: actions/setup-node@v2-beta
         with:

.github/workflows/update-parser-tests.yml

@@ -38,7 +38,7 @@ jobs:
           echo ${{ steps.test262.outputs.sha1 }} | ./scripts/parser-tests/bump-test262-version.sh
       - name: Build babel parser
         run: |
-          yarn install --immutable --skip-builds
+          yarn install --immutable --mode=skip-build
           yarn gulp build-rollup
       - name: Update test262 allow list
         run: |