Merge pull request rails#28187 from kamipo/fix_intermittent_test_failure

Fix `test_apply_distinct_in_count` failure in PG adapter

Author: pixeltrix

activerecord/test/cases/calculations_test.rb

@@ -234,6 +234,9 @@ def test_apply_distinct_in_count
     end
 
     queries.each do |query|
+      # `table_alias_length` in `column_alias_for` would execute
+      # "SHOW max_identifier_length" statement in PostgreSQL adapter.
+      next if query == "SHOW max_identifier_length"
       assert_match %r{\ASELECT(?! DISTINCT) COUNT\(DISTINCT\b}, query
     end
   end