collab: Remove unused Signup model (#44438)

This PR removes the `Signup` database model, as it was not being used.

Release Notes:

- N/A

crates/collab/src/db/tables.rs

@@ -22,7 +22,6 @@ pub mod project_repository_statuses;
 pub mod room;
 pub mod room_participant;
 pub mod server;
-pub mod signup;
 pub mod user;
 pub mod worktree;
 pub mod worktree_diagnostic_summary;

crates/collab/src/db/tables/signup.rs

@@ -1,28 +0,0 @@
-use crate::db::{SignupId, UserId};
-use sea_orm::entity::prelude::*;
-
-#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
-#[sea_orm(table_name = "signups")]
-pub struct Model {
-    #[sea_orm(primary_key)]
-    pub id: SignupId,
-    pub email_address: String,
-    pub email_confirmation_code: String,
-    pub email_confirmation_sent: bool,
-    pub created_at: DateTime,
-    pub device_id: Option<String>,
-    pub user_id: Option<UserId>,
-    pub inviting_user_id: Option<UserId>,
-    pub platform_mac: bool,
-    pub platform_linux: bool,
-    pub platform_windows: bool,
-    pub platform_unknown: bool,
-    pub editor_features: Option<Vec<String>>,
-    pub programming_languages: Option<Vec<String>>,
-    pub added_to_mailing_list: bool,
-}
-
-#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
-pub enum Relation {}
-
-impl ActiveModelBehavior for ActiveModel {}