fix mysql migrations

db/migrate/20250915060548_create_lock_events.rb

@@ -6,7 +6,8 @@ class CreateLockEvents < ActiveRecord::Migration[8.0]
       t.string :key, index: true, null: false
       t.string :event_name, null: false
 
-      t.index %i[event_name key], unique: adapter_name != 'Mysql2', where: "event_name IN ('start', 'complete')"
+      t.index %i[event_name key], unique: connection.supports_partial_index?,
+                                  where: "event_name IN ('start', 'complete')"
 
       t.timestamps
     end

db/migrate/20251121092044_add_is_first_to_completed_submitters.rb

@@ -10,7 +10,7 @@ class AddIsFirstToCompletedSubmitters < ActiveRecord::Migration[8.0]
               where: 'is_first = TRUE',
               name: 'index_completed_submitters_account_id_completed_at_is_first'
 
-    add_index :completed_submitters, :submission_id, unique: adapter_name != 'Mysql2',
+    add_index :completed_submitters, :submission_id, unique: connection.supports_partial_index?,
                                                      where: 'is_first = TRUE'
   end
 end