Remove unnecessary `test_sql_for_insert_with_returning_disabled`

Because `sql_for_insert` is only called in `use_insert_returning?` is
true since #26002.

1 files changed, 2 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
index 46aca2ab54..7414eba6c5 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
@@ -124,14 +124,13 @@ module ActiveRecord
             pk = primary_key(table_ref) if table_ref
           end
 
-          pk = suppress_composite_primary_key(pk)
-
-          if pk && use_insert_returning?
+          if pk = suppress_composite_primary_key(pk)
             sql = "#{sql} RETURNING #{quote_column_name(pk)}"
           end
 
           super
         end
+        protected :sql_for_insert
 
         def exec_insert(sql, name = nil, binds = [], pk = nil, sequence_name = nil)
           if use_insert_returning? || pk == false