Replace entity.manager with entity_type.manager

Problem/Motivation

On Drupal 9, I am getting a WSOD

Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException: You have requested a non-existent service "entity.manager". in Drupal\Component\DependencyInjection\Container->get() (line 156 of drupal9.2.19/html/core/lib/Drupal/Component/DependencyInjection/Container.php).

this is the line of code:
contrib/invite/src/Form/InviteForm.php:49: $container->get('entity.manager'),

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes