Disable schema dumping after migrations in production

The change from `db/schema.rb` to `db/structure.sql` requires `pg_dump`,
which can fail if the `pg_dump` version used is older than the
PostgreSQL server that is running.

We now disable schema dumping after migrations for production;
development still does this by default. This can be invoked directly via
`rake db:schema:dump`.

This should address
https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/5299.

changelogs/unreleased/sh-disable-schema-dump-prod.yml

+---
+title: Disable schema dumping after migrations in production
+merge_request: 30812
+author:
+type: fixed

config/environments/production.rb

@@ -52,6 +52,9 @@ Rails.application.configure do
   # Enable serving of images, stylesheets, and JavaScripts from an asset server
   config.action_controller.asset_host = ENV['GITLAB_CDN_HOST'] if ENV['GITLAB_CDN_HOST'].present?
 
+  # Do not dump schema after migrations.
+  config.active_record.dump_schema_after_migration = false
+
   # Precompile additional assets (application.js, application.css, and all non-JS/CSS are already added)
   # config.assets.precompile += %w( search.js )