added vespa provider reference to extra-packages

Author: radu-gheorghe

airflow-core/docs/extra-packages-ref.rst

@@ -299,6 +299,8 @@ These are extras that add dependencies needed for integration with external serv
 +---------------------+-----------------------------------------------------+-----------------------------------------------------+
 | vertica             | ``pip install 'apache-airflow[vertica]'``           | Vertica hook support as an Airflow backend          |
 +---------------------+-----------------------------------------------------+-----------------------------------------------------+
+| vespa               | ``pip install 'apache-airflow[vespa]'``             | Vespa hooks and operators                           |
++---------------------+-----------------------------------------------------+-----------------------------------------------------+
 | weaviate            | ``pip install 'apache-airflow[weaviate]'``          | Weaviate hook and operators                         |
 +---------------------+-----------------------------------------------------+-----------------------------------------------------+
 | yandex              | ``pip install 'apache-airflow[yandex]'``            | Yandex.cloud hooks and operators                    |