Update PostgreSQL version in build workflow

Author: gugu

.github/workflows/build.yaml

@@ -19,7 +19,7 @@ jobs:
     strategy:
       matrix:
         include:
-          - postgres_version: "16"
+          - postgres_version: "16.11"
             # renovate datasource=docker depName=ghcr.io/cloudnative-pg/postgresql
             cnpg_version: 16.11
             latest: "true"