Merge pull request #28531 from yahonda/suppress_pg_warning

Suppress `WARNING:  nonstandard use of \\ in a string literal` warning

activerecord/test/cases/adapters/postgresql/bytea_test.rb

@@ -89,6 +89,7 @@ def test_via_to_sql_with_complicating_connection
     Thread.new do
       other_conn = ActiveRecord::Base.connection
       other_conn.execute("SET standard_conforming_strings = off")
+      other_conn.execute("SET escape_string_warning = off")
     end.join
 
     test_via_to_sql