Do not save user preferences on read-only mode

What does this MR do?

Geo secondaries are in read only mode, so modifying the database in GET requests throws 500 errors.

closes #55024 (closed)

Idea for the future

We should probably add a spec to prevent this from happening.

I tried to wrap :get method from rspec using:

module DatabaseReadOnlyCheck
  def get(*)
    previous_changes = changes_count

    super

    if previous_changes != changes_count
      raise("Changes made")
    end
  end

  def changes_count
    database_name = Rails.configuration.database_configuration[Rails.env]["database"]

    changes =
      ActiveRecord::Base.connection.execute <<-SQL
        SELECT tup_inserted, tup_updated, tup_deleted FROM pg_stat_database
        WHERE datname = '#{database_name}'
      SQL

    changes.first
  end
end

But postgres takes a while to udpate pg_stat_database which does not fail the specs. Any idea here would be appreciated.