Simplified CI

.github/workflows/build.yml

@@ -10,10 +10,6 @@ jobs:
         postgres: [13, 12, 11, 10, 9.6]
     steps:
     - uses: actions/checkout@v2
-    - run: |
-        sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
-        wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
-        sudo apt-get update
     - uses: ankane/setup-postgres@v1
       with:
         postgres-version: ${{ matrix.postgres }}