Add mutex to storing column details

app/models/concerns/ignorable_columns.rb

@@ -23,12 +23,12 @@ module IgnorableColumns
 
       self.ignored_columns += columns.flatten # rubocop:disable Cop/IgnoredColumns
 
-      unless defined?(@ignored_columns_details)
-        @ignored_columns_details = superclass.try(:ignored_columns_details)&.dup || {}
-      end
+      IGNORE_COLUMN_MUTEX.synchronize do
+        @ignored_columns_details ||= superclass.try(:ignored_columns_details)&.dup || {}
 
-      columns.flatten.each do |column|
-        @ignored_columns_details[column.to_sym] = ColumnIgnore.new(Date.parse(remove_after), remove_with)
+        columns.flatten.each do |column|
+          @ignored_columns_details[column.to_sym] = ColumnIgnore.new(Date.parse(remove_after), remove_with)
+        end
       end
     end
 
@@ -37,5 +37,7 @@ module IgnorableColumns
     def ignored_columns_details
       @ignored_columns_details || {}
     end
+
+    IGNORE_COLUMN_MUTEX = Mutex.new
   end
 end