chore: move pg string to env

.github/workflows/infra-build.yml

@@ -12,6 +12,9 @@ jobs:
     container:
       image: node:20-bullseye
     
+    env:
+      PG_CONN_STR: ${{ secrets.PG_CONN_STR }}   # available to all steps
+     
     steps:
       - name: Checkout code
         uses: actions/checkout@v5
@@ -45,7 +48,6 @@ jobs:
       - name: Opentofu Plan
         id: plan
         run: |
-          export PG_CONN_STR="${{ secrets.PG_CONN_STR }}"
           tofu plan -out=tfplan -detailed-exitcode
 
       - name: Opentofu Apply