chore: create index in separate migration

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    dashboard (0.1.16)
+    dashboard (0.1.17)
       bcrypt_pbkdf
       cssbundling-rails
       ed25519

db/migrate/20240103232412_create_dashboard_academic_years.rb

@@ -5,7 +5,5 @@ class CreateDashboardAcademicYears < ActiveRecord::Migration[7.1]
 
       t.timestamps
     end
-    remove_index :dashboard_academic_years, :range
-    add_index :dashboard_academic_years, :range, unique: true
   end
 end

db/migrate/20240209235612_add_unique_index_to_dashboard_academic_year.rb

@@ -0,0 +1,5 @@
+class AddUniqueIndexToDashboardAcademicYear < ActiveRecord::Migration[7.1]
+  def change
+    add_index :dashboard_academic_years, :range, unique: true
+  end
+end

lib/dashboard/version.rb

@@ -1,3 +1,3 @@
 module Dashboard
-  VERSION = "0.1.17"
+  VERSION = "0.1.18"
 end