Return row-count for pluck

[aidanharan]

Fix:

https://github.com/rails-sqlserver/activerecord-sqlserver-adapter/actions/runs/9061194112/job/24892482330

25) Error:
ActiveRecord::InstrumentationTest#test_payload_row_count_on_pluck:
ActiveRecord::RecordNotUnique: TinyTds::Error: Cannot insert duplicate key row in object 'dbo.books' with unique index 'index_books_on_author_id_and_name'. The duplicate key value is (<NULL>, row count book 2).
    /activerecord-sqlserver-adapter/lib/active_record/connection_adapters/sqlserver/database_statements.rb:433:in `each'
    /activerecord-sqlserver-adapter/lib/active_record/connection_adapters/sqlserver/database_statements.rb:433:in `handle_to_names_and_values'
    /activerecord-sqlserver-adapter/lib/active_record/connection_adapters/sqlserver/database_statements.rb:60:in `internal_exec_sql_query'
    /activerecord-sqlserver-adapter/lib/active_record/connection_adapters/sqlserver/database_statements.rb:48:in `block (2 levels) in internal_exec_query'
    /usr/local/bundle/bundler/gems/rails-dae4867b3350/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb:997:in `block in with_raw_connection'
    /usr/local/bundle/bundler/gems/rails-dae4867b3350/activesupport/lib/active_support/c