Remove add_column_with_default from template

- since this method is deprecated we shouldn't
mention it in guidance as it can be confusing

generator_templates/active_record/migration/create_table_migration.rb

@@ -14,8 +14,8 @@ class <%= migration_class_name %> < ActiveRecord::Migration[<%= ActiveRecord::Mi
   # migration requires downtime.
   # DOWNTIME_REASON = ''
 
-  # When using the methods "add_concurrent_index", "remove_concurrent_index" or
-  # "add_column_with_default" you must disable the use of transactions
+  # When using the methods "add_concurrent_index" or "remove_concurrent_index"
+  # you must disable the use of transactions
   # as these methods can not run in an existing transaction.
   # When using "add_concurrent_index" or "remove_concurrent_index" methods make sure
   # that either of them is the _only_ method called in the migration,

generator_templates/active_record/migration/migration.rb

@@ -15,8 +15,8 @@ class <%= migration_class_name %> < ActiveRecord::Migration[<%= ActiveRecord::Mi
   # migration requires downtime.
   # DOWNTIME_REASON = ''
 
-  # When using the methods "add_concurrent_index", "remove_concurrent_index" or
-  # "add_column_with_default" you must disable the use of transactions
+  # When using the methods "add_concurrent_index" or "remove_concurrent_index"
+  # you must disable the use of transactions
   # as these methods can not run in an existing transaction.
   # When using "add_concurrent_index" or "remove_concurrent_index" methods make sure
   # that either of them is the _only_ method called in the migration,

generator_templates/rails/post_deployment_migration/migration.rb

@@ -9,8 +9,8 @@ class <%= migration_class_name %> < ActiveRecord::Migration[<%= ActiveRecord::Mi
 
   DOWNTIME = false
 
-  # When using the methods "add_concurrent_index", "remove_concurrent_index" or
-  # "add_column_with_default" you must disable the use of transactions
+  # When using the methods "add_concurrent_index" or "remove_concurrent_index"
+  # you must disable the use of transactions
   # as these methods can not run in an existing transaction.
   # When using "add_concurrent_index" or "remove_concurrent_index" methods make sure
   # that either of them is the _only_ method called in the migration,