Add issue_7896 test cases to regression suite for improved coverage

src/test/regress/multi_mx_schedule

@@ -69,6 +69,7 @@ test: local_shard_execution_dropped_column
 test: metadata_sync_helpers
 
 test: issue_6592
+test: issue_7896
 test: executor_local_failure
 
 # test that no tests leaked intermediate results. This should always be last

src/test/regress/multi_schedule

@@ -105,7 +105,7 @@ test: binary_protocol
 test: alter_table_set_access_method
 test: alter_distributed_table
 test: issue_5248 issue_5099 issue_5763 issue_6543 issue_6758 issue_7477 issue_7891
-test: issue_7896
+
 test: object_propagation_debug
 test: undistribute_table
 test: run_command_on_all_nodes

src/test/regress/sql/issue_7896.sql

@@ -14,6 +14,7 @@
 ---------------------------------------------------------------------
 -- 1) Setup the test environment.
 ---------------------------------------------------------------------
+SET citus.next_shard_id TO 17560000;
 CREATE SCHEMA issue_7896;
 SET search_path TO issue_7896;