ci: set DATABASE_URL globally for test job

- Move MIX_ENV and DATABASE_URL to job-level env vars
- Removes need to set them on individual steps
- Ensures all database operations use correct hostname (postgres)
- Fixes 'connection refused' errors from hardcoded localhost in test.exs

.forgejo/workflows/build.yaml

@@ -16,6 +16,9 @@ concurrency:
 jobs:
   test:
     runs-on: ubuntu-22.04
+    env:
+      MIX_ENV: test
+      DATABASE_URL: postgresql://postgres:postgres@postgres:5432/towerops_test
     services:
       postgres:
         image: timescale/timescaledb:latest-pg17
@@ -84,26 +87,18 @@ jobs:
 
       - name: Setup database
         run: mix ecto.create
-        env:
-          MIX_ENV: test
-          DATABASE_URL: postgresql://postgres:postgres@postgres:5432/towerops_test
 
       - name: Check code formatting
         run: mix format --check-formatted
 
       - name: Compile with warnings as errors
         run: mix compile --warnings-as-errors
-        env:
-          MIX_ENV: test
 
       - name: Run Credo
         run: mix credo --strict
 
       - name: Run tests
         run: mix test --warnings-as-errors
-        env:
-          MIX_ENV: test
-          DATABASE_URL: postgresql://postgres:postgres@postgres:5432/towerops_test
 
   build:
     runs-on: ubuntu-22.04