remove db var exports from CI test setup; no longer necessary since getodk/central#1671 (#1494)

Author: brontolosone

.github/workflows/tests.yml

@@ -64,10 +64,6 @@ jobs:
         sed -i 's|\${BASE_URL}|http://${DOMAIN}|g' files/service/config.json.template
         sed -i 's/\$scheme/https/g' files/nginx/backend.conf
         sed 's/your.domain.com/central-test.localhost/; s/^SSL_TYPE=letsencrypt/SSL_TYPE=upstream/' .env.template > .env
-        echo PGHOST=postgres14 >> .env
-        echo PGUSER=odk >> .env
-        echo PGPASSWORD=odk >> .env
-        echo PGPORT=5432 >> .env
     - name: Add domain
       run: echo '127.0.0.1 central-test.localhost' | sudo tee --append /etc/hosts
     - name: Start services