ci: update backend test workflow with working directory and path adjustments

- Rename job from `test` to `test-backend`
- Set `working-directory` to `/backend` for consistency
- Adjust `APP_BASE_FOLDER_PATH` to reflect relative file path changes

Author: Pdzly

.github/workflows/test-backend.yml

@@ -9,8 +9,11 @@ on:
       - master
 
 jobs:
-  test:
+  test-backend:
     runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./backend
     services:
       postgres:
         image: postgres:16
@@ -46,7 +49,7 @@ jobs:
       - name: Run tests
         env:
           APP_DATABASE_URL: postgresql+asyncpg://postgres:postgres@localhost:5433/devbin_test
-          APP_BASE_FOLDER_PATH: /tmp/devbin_test_files
+          APP_BASE_FOLDER_PATH: ./files/devbin_test_files
           APP_DEBUG: "true"
           APP_CORS_DOMAINS: '["http://test"]'
           APP_ALLOW_CORS_WILDCARD: "false"