chore: updating migrations again and making simpler

Signed-off-by: benjdlambert <ben@blam.sh>

plugins/auth-backend/migrations/20250707164600_user_created_at.js

@@ -22,25 +22,7 @@
 exports.up = async function up(knex) {
   await knex.schema.alterTable('user_info', table => {
     table.renameColumn('exp', 'updated_at');
-  });
-
-  // Sqlite doesn't support adding a column with non-constant default when table has data
-  // so we need to add it as nullable first, then set the value to the updated_at value
-  await knex.schema.alterTable('user_info', table => {
-    table.timestamp('created_at').nullable();
-  });
-
-  await knex('user_info').update({
-    created_at: knex.ref('updated_at'),
-  });
-
-  // Then alter to non-nullable and set the default to now()
-  await knex.schema.alterTable('user_info', table => {
-    table
-      .timestamp('created_at')
-      .notNullable()
-      .defaultTo(knex.fn.now())
-      .alter();
+    table.timestamp('created_at').notNullable().defaultTo(knex.fn.now());
   });
 };