Add YARN_ENABLE_IMMUTABLE_INSTALLS: "false" to CI

Author: aryaemami59

.github/workflows/tests.yml

@@ -163,6 +163,8 @@ jobs:
     defaults:
       run:
         working-directory: ./examples/publish-ci/${{ matrix.example }}
+    env:
+      YARN_ENABLE_IMMUTABLE_INSTALLS: "false"
     steps:
       - name: Checkout repo
         uses: actions/checkout@v2