9 files declare their use of ActivityFactory in Open Social 10.0.x

ActivityContextBase.php in modules/custom/activity_creator/src/Plugin/ActivityContextBase.php

ActivityWorkerActivities.php in modules/custom/activity_creator/src/Plugin/QueueWorker/ActivityWorkerActivities.php

EventInviteActivityContext.php in modules/social_features/social_event/modules/social_event_invite/src/Plugin/ActivityContext/EventInviteActivityContext.php

EventRequestActivityContext.php in modules/custom/activity_basics/src/Plugin/ActivityContext/EventRequestActivityContext.php

FollowTaxonomyActivityContext.php in modules/social_features/social_follow_taxonomy/src/Plugin/ActivityContext/FollowTaxonomyActivityContext.php

GroupActivityContext.php in modules/custom/activity_basics/src/Plugin/ActivityContext/GroupActivityContext.php

GroupContentInMyGroupActivityContext.php in modules/custom/activity_basics/src/Plugin/ActivityContext/GroupContentInMyGroupActivityContext.php

OrganizerActivityContext.php in modules/custom/activity_basics/src/Plugin/ActivityContext/OrganizerActivityContext.php

PrivateMessageActivityContext.php in modules/social_features/social_private_message/src/Plugin/ActivityContext/PrivateMessageActivityContext.php