DEV: Protection for migrations that creates index concurrently take 2 (#31792)

This is a follow up to 6820622467ab3613e824f0cb6219def2a575bc1d.

This commit addresses migrations that uses `remove_index` with the
`if_exists: true` option to drop an existing index before creating an
index using the `concurrently` option.

This commit also reruns two migration which may have caused indexes to
be left in an `invalid` state.

### Reviewers Note

Plugin tests are failing due to
https://github.com/discourse/discourse-translator/pull/251

db/migrate/20241115143259_add_index_to_users_ip_address.rb

@@ -1,9 +0,0 @@
-# frozen_string_literal: true
-
-class AddIndexToUsersIpAddress < ActiveRecord::Migration[7.1]
-  disable_ddl_transaction!
-
-  def change
-    add_index :users, :ip_address, algorithm: :concurrently, name: "idx_users_ip_address"
-  end
-end

db/migrate/20250313044812_remove_unique_constraint_from_tag_users_indexes.rb

@@ -1,10 +1,21 @@
 # frozen_string_literal: true
+
 class RemoveUniqueConstraintFromTagUsersIndexes < ActiveRecord::Migration[7.1]
   disable_ddl_transaction!
 
   def up
-    remove_index :tag_users, name: :idx_tag_users_ix1, algorithm: :concurrently
-    remove_index :tag_users, name: :idx_tag_users_ix2, algorithm: :concurrently
+    remove_index :tag_users, name: :idx_tag_users_ix1, algorithm: :concurrently, if_exists: true
+    remove_index :tag_users, name: :idx_tag_users_ix2, algorithm: :concurrently, if_exists: true
+
+    remove_index :tag_users,
+                 %i[user_id tag_id notification_level],
+                 algorithm: :concurrently,
+                 if_exists: true
+
+    remove_index :tag_users,
+                 %i[tag_id user_id notification_level],
+                 algorithm: :concurrently,
+                 if_exists: true
 
     add_index :tag_users, %i[user_id tag_id notification_level], algorithm: :concurrently
     add_index :tag_users, %i[tag_id user_id notification_level], algorithm: :concurrently

db/migrate/20250313045010_add_index_to_users_ip_address.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class AddIndexToUsersIpAddress < ActiveRecord::Migration[7.1]
+  disable_ddl_transaction!
+
+  def up
+    remove_index :users,
+                 :ip_address,
+                 algorithm: :concurrently,
+                 name: "idx_users_ip_address",
+                 if_exists: true
+
+    add_index :users, :ip_address, algorithm: :concurrently, name: "idx_users_ip_address"
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end