Add Bun installation step to E2E test workflow

Author: MalithaPrabhashana

.github/workflows/e2e-tests.yml

@@ -34,6 +34,9 @@ jobs:
         with:
           node-version: "20"
 
+      - name: Install Bun
+        uses: oven-sh/setup-bun@v2
+
       - name: Install Jac and dependencies
         run: |
           pip install jaclang jac-client jac-scale pytest pytest-playwright pytest-timeout