DEV: Promote historic post_deploy migrations for core plugins. (#30987)

This commit promotes all post_deploy migrations which existed in
Discourse v3.3.0 (timestamp <= 20240717053710)

plugins/styleguide/db/migrate/20240122015630_fill_styleguide_admin_only_groups.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+class FillStyleguideAdminOnlyGroups < ActiveRecord::Migration[7.0]
+  def up
+    old_setting =
+      DB.query_single(
+        "SELECT value FROM site_settings WHERE name = 'styleguide_admin_only' LIMIT 1",
+      ).first
+
+    if old_setting.present?
+      allowed_groups = old_setting == "t" ? "1" : "14" # use admins AUTO_GROUP if true, otherwise default to TL4
+
+      DB.exec(
+        "INSERT INTO site_settings(name, value, data_type, created_at, updated_at)
+        VALUES('styleguide_allowed_groups', :setting, '20', NOW(), NOW())",
+        setting: allowed_groups,
+      )
+    end
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end