Purge old PG client version(s)

.github/workflows/test.yml

@@ -13,6 +13,7 @@ jobs:
       run: |
         sudo apt install -y postgresql-common
         sudo /usr/share/postgresql-common/pgdg/apt.postgresql.org.sh -y
+        sudo apt purge -y postgresql-client-common
         sudo apt install -y postgresql-client
     - name: Checkout source
       uses: actions/checkout@v2