Reduce log level to avoid alternative output for PG15 (#6118)

We are reducing the log level here to avoid alternative test output
in PG15 because of the change in the display of SQL-standard
function's arguments in INSERT/SELECT in PG15.
The log level changes can be reverted when we drop support for PG14
Relevant PG commit:
a8d8445a7b2f80f6d0bfe97b19f90bd2cbef8759

src/test/regress/expected/replicate_reference_tables_to_coordinator.out

@@ -472,8 +472,13 @@ BEGIN;
 INSERT INTO local_table VALUES (1), (2), (3);
 INSERT INTO numbers SELECT * FROM generate_series(1, 100);
 NOTICE:  executing the copy locally for shard xxxxx
+-- We are reducing the log level here to avoid alternative test output
+-- in PG15 because of the change in the display of SQL-standard
+-- function's arguments in INSERT/SELECT in PG15.
+-- The log level changes can be reverted when we drop support for PG14
+SET client_min_messages TO WARNING;
 INSERT INTO numbers SELECT * FROM numbers;
-NOTICE:  executing the command locally: INSERT INTO replicate_ref_to_coordinator.numbers_8000001 AS citus_table_alias (a) SELECT a FROM replicate_ref_to_coordinator.numbers_8000001 numbers
+RESET client_min_messages;
 SELECT COUNT(*) FROM local_table JOIN numbers using (a);
 NOTICE:  executing the command locally: SELECT count(*) AS count FROM (replicate_ref_to_coordinator.local_table JOIN replicate_ref_to_coordinator.numbers_8000001 numbers(a) USING (a))
  count

src/test/regress/expected/with_dml.out

@@ -118,6 +118,11 @@ DEBUG:  Collecting INSERT ... SELECT results on coordinator
 -- otherwise the coordinator insert select fails
 -- since COPY cannot be executed
 SET citus.force_max_query_parallelization TO on;
+-- We are reducing the log level here to avoid alternative test output
+-- in PG15 because of the change in the display of SQL-standard
+-- function's arguments in INSERT/SELECT in PG15.
+-- The log level changes can be reverted when we drop support for PG14
+SET client_min_messages TO LOG;
 WITH copy_to_other_table AS (
     INSERT INTO distributed_table
         SELECT *
@@ -141,13 +146,8 @@ INSERT INTO second_distributed_table
         EXCEPT
         SELECT *
             FROM copy_to_other_table;
-DEBUG:  distributed INSERT ... SELECT can only select from distributed tables
-DEBUG:  generating subplan XXX_1 for CTE copy_to_other_table: INSERT INTO with_dml.distributed_table (tenant_id, dept) SELECT tenant_id, dept FROM with_dml.second_distributed_table WHERE (dept OPERATOR(pg_catalog.=) 3) ON CONFLICT(tenant_id) DO UPDATE SET dept = 4 RETURNING distributed_table.tenant_id, distributed_table.dept
-DEBUG:  generating subplan XXX_2 for CTE main_table_deleted: DELETE FROM with_dml.distributed_table WHERE ((dept OPERATOR(pg_catalog.<) 10) AND (NOT (EXISTS (SELECT 1 FROM with_dml.second_distributed_table WHERE ((second_distributed_table.dept OPERATOR(pg_catalog.=) 1) AND (second_distributed_table.tenant_id OPERATOR(pg_catalog.=) distributed_table.tenant_id)))))) RETURNING tenant_id, dept
-DEBUG:  generating subplan XXX_3 for subquery SELECT main_table_deleted.tenant_id, main_table_deleted.dept FROM (SELECT intermediate_result.tenant_id, intermediate_result.dept FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(tenant_id text, dept integer)) main_table_deleted EXCEPT SELECT copy_to_other_table.tenant_id, copy_to_other_table.dept FROM (SELECT intermediate_result.tenant_id, intermediate_result.dept FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(tenant_id text, dept integer)) copy_to_other_table
-DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT tenant_id, dept FROM (SELECT intermediate_result.tenant_id, intermediate_result.dept FROM read_intermediate_result('XXX_3'::text, 'binary'::citus_copy_format) intermediate_result(tenant_id text, dept integer)) citus_insert_select_subquery
-DEBUG:  Collecting INSERT ... SELECT results on coordinator
 SET citus.force_max_query_parallelization TO off;
+SET client_min_messages TO DEBUG1;
 -- CTE inside the UPDATE statement
 UPDATE
 	second_distributed_table

src/test/regress/sql/replicate_reference_tables_to_coordinator.sql

@@ -229,7 +229,13 @@ ROLLBACK;
 BEGIN;
 INSERT INTO local_table VALUES (1), (2), (3);
 INSERT INTO numbers SELECT * FROM generate_series(1, 100);
+-- We are reducing the log level here to avoid alternative test output
+-- in PG15 because of the change in the display of SQL-standard
+-- function's arguments in INSERT/SELECT in PG15.
+-- The log level changes can be reverted when we drop support for PG14
+SET client_min_messages TO WARNING;
 INSERT INTO numbers SELECT * FROM numbers;
+RESET client_min_messages;
 SELECT COUNT(*) FROM local_table JOIN numbers using (a);
 UPDATE numbers SET a = a + 1;
 SELECT COUNT(*) FROM local_table JOIN numbers using (a);

src/test/regress/sql/with_dml.sql

@@ -97,6 +97,11 @@ INSERT INTO distributed_table
 -- otherwise the coordinator insert select fails
 -- since COPY cannot be executed
 SET citus.force_max_query_parallelization TO on;
+-- We are reducing the log level here to avoid alternative test output
+-- in PG15 because of the change in the display of SQL-standard
+-- function's arguments in INSERT/SELECT in PG15.
+-- The log level changes can be reverted when we drop support for PG14
+SET client_min_messages TO LOG;
 WITH copy_to_other_table AS (
     INSERT INTO distributed_table
         SELECT *
@@ -122,6 +127,7 @@ INSERT INTO second_distributed_table
             FROM copy_to_other_table;
 
 SET citus.force_max_query_parallelization TO off;
+SET client_min_messages TO DEBUG1;
 
 -- CTE inside the UPDATE statement
 UPDATE