Bulk import of event volunteers, speakers via CSV and drush

Tested with the following CSV:

1,speaker
2,speake
fake-user@fake-email.com,organizer
drumm,volunteer
b_man,organizer

Then ran it for event https://fjgarlin-drupal.dev.devdrupal.org/community/events/midcamp-2025-...
Like this drush drupalorg-event-volunteers 3443832 ./test.csv -v

$ drush drupalorg-event-volunteers 3443832 ./test.csv -v
Adding user 1 as field_event_speakers.                                                                                                                  [notice]
Adding user 2 as field_event_volunteers.                                                                                                                [notice]
Adding user 3064 as field_event_volunteers.                                                                                                             [notice]
Adding user 2689807 as field_organizers.                                                                                                                [notice]
Saving event.                                                                                                                                           [notice]
The following users could not be matched: fake-user@fake-email.com.    

Deployed!

Automatically closed - issue fixed for 2 weeks with no activity.