Test GH Actions env context

.github/workflows/publish-main.yml

@@ -1,23 +1,14 @@
-name: Publish main
+name: Test
 
 on:
   push:
-    branches: [main]
 
 jobs:
-  publish:
+  test:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - name: '[node LTS] npm install'
-      uses: ljharb/actions/node/install@main
-      with:
-        node-version: lts/*
-    - run: npm run build
-    - name: Publish to gh-pages
-      uses: JamesIves/[email protected]
-      with:
-        branch: gh-pages
-        folder: build
-        clean-exclude: |
-          pr
+    - run: echo "CUSTOM_FOO=foo" >> "$GITHUB_ENV"
+    - env:
+        CUSTOM_BAR: ${{ env.CUSTOM_FOO }}
+        CUSTOM_BAZ: "::${{ env.CUSTOM_FOO }}::"
+      run: "env | grep CUSTOM_"