adapt migration for mysql5.7

db/migrations/20240808118000_drop_unique_constraint_quota_definitions_name_key.rb

@@ -1,6 +1,15 @@
 Sequel.migration do
   up do
     if self.class.name.match?(/mysql/i)
+      mysql_version = server_version
+      if mysql_version < 80_000 # MySQL 5.7 and below
+        alter_table :quota_definitions do
+          # rubocop:disable Sequel/ConcurrentIndex
+          # Drop the index only for MySQL 5.7
+          drop_index :name, name: :name if @db.indexes(:quota_definitions).include?(:name)
+          # rubocop:enable Sequel/ConcurrentIndex
+        end
+      end
       alter_table :quota_definitions do
         drop_constraint :name, if_exists: true
       end

spec/migrations/20240808118000_drop_unique_constraint_quota_definitions_name_key_spec.rb

@@ -5,6 +5,7 @@
   include_context 'migration' do
     let(:migration_filename) { '20240808118000_drop_unique_constraint_quota_definitions_name_key_spec.rb' }
   end
+
   describe 'up migration' do
     context 'unique constraint on name column exists' do
       it 'removes the unique constraint' do