collab: Make users.github_user_id required and unique (#16704)

This PR makes the `github_user_id` column on the `users` table required
and replaces the index with a unique index.

I have gone through and ensured that all users have a unique
`github_user_id` in the staging and production databases.

Release Notes:

- N/A

crates/collab/src/db/tests/buffer_tests.rs

@@ -42,7 +42,7 @@ async fn test_channel_buffers(db: &Arc<Database>) {
             false,
             NewUserParams {
                 github_login: "user_c".into(),
-                github_user_id: 102,
+                github_user_id: 103,
             },
         )
         .await

crates/collab/src/db/tests/contributor_tests.rs

@@ -25,7 +25,7 @@ async fn test_contributors(db: &Arc<Database>) {
     assert_eq!(db.get_contributors().await.unwrap(), Vec::<String>::new());
 
     let user1_created_at = Utc::now();
-    db.add_contributor("user1", Some(1), None, Some(user1_created_at), None)
+    db.add_contributor("user1", 1, None, Some(user1_created_at), None)
         .await
         .unwrap();
     assert_eq!(
@@ -34,7 +34,7 @@ async fn test_contributors(db: &Arc<Database>) {
     );
 
     let user2_created_at = Utc::now();
-    db.add_contributor("user2", Some(2), None, Some(user2_created_at), None)
+    db.add_contributor("user2", 2, None, Some(user2_created_at), None)
         .await
         .unwrap();
     assert_eq!(

crates/collab/src/db/tests/db_tests.rs

@@ -45,25 +45,25 @@ async fn test_get_users(db: &Arc<Database>) {
             (
                 user_ids[0],
                 "user1".to_string(),
-                Some(1),
+                1,
                 Some("user1@example.com".to_string()),
             ),
             (
                 user_ids[1],
                 "user2".to_string(),
-                Some(2),
+                2,
                 Some("user2@example.com".to_string()),
             ),
             (
                 user_ids[2],
                 "user3".to_string(),
-                Some(3),
+                3,
                 Some("user3@example.com".to_string()),
             ),
             (
                 user_ids[3],
                 "user4".to_string(),
-                Some(4),
+                4,
                 Some("user4@example.com".to_string()),
             )
         ]
@@ -101,23 +101,17 @@ async fn test_get_or_create_user_by_github_account(db: &Arc<Database>) {
         .user_id;
 
     let user = db
-        .get_or_create_user_by_github_account(
-            "the-new-login2",
-            Some(102),
-            None,
-            Some(Utc::now()),
-            None,
-        )
+        .get_or_create_user_by_github_account("the-new-login2", 102, None, Some(Utc::now()), None)
         .await
         .unwrap();
     assert_eq!(user.id, user_id2);
     assert_eq!(&user.github_login, "the-new-login2");
-    assert_eq!(user.github_user_id, Some(102));
+    assert_eq!(user.github_user_id, 102);
 
     let user = db
         .get_or_create_user_by_github_account(
             "login3",
-            Some(103),
+            103,
             Some("user3@example.com"),
             Some(Utc::now()),
             None,
@@ -125,7 +119,7 @@ async fn test_get_or_create_user_by_github_account(db: &Arc<Database>) {
         .await
         .unwrap();
     assert_eq!(&user.github_login, "login3");
-    assert_eq!(user.github_user_id, Some(103));
+    assert_eq!(user.github_user_id, 103);
     assert_eq!(user.email_address, Some("user3@example.com".into()));
 }