chore: Upgrade to Rails 7 (#6719)

fixes: #6736

db/migrate/20230321073727_remove_not_null_on_active_storage_blobs_checksum.active_storage.rb

@@ -0,0 +1,8 @@
+# This migration comes from active_storage (originally 20211119233751)
+class RemoveNotNullOnActiveStorageBlobsChecksum < ActiveRecord::Migration[6.0]
+  def change
+    return unless table_exists?(:active_storage_blobs)
+
+    change_column_null(:active_storage_blobs, :checksum, true)
+  end
+end