Fix pg 1.5 deprecation warning

Closes rails#48046

Author: morgoth

Gemfile.lock

@@ -358,7 +358,7 @@ GEM
     parser (3.2.1.1)
       ast (~> 2.4.1)
     path_expander (1.1.1)
-    pg (1.4.5)
+    pg (1.5.1)
     propshaft (0.6.4)
       actionpack (>= 7.0.0)
       activesupport (>= 7.0.0)

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -1096,7 +1096,7 @@ def update_typemap_for_default_timezone
               PG::TextDecoder::TimestampUtc :
               PG::TextDecoder::TimestampWithoutTimeZone
 
-            @timestamp_decoder = decoder_class.new(@timestamp_decoder.to_h)
+            @timestamp_decoder = decoder_class.new(**@timestamp_decoder.to_h)
             @raw_connection.type_map_for_results.add_coder(@timestamp_decoder)
 
             @mapped_default_timezone = default_timezone