Temporarily disable connection leak tests that fail a lot (#3911)

MX connection leak failures:
1. https://app.circleci.com/pipelines/github/citusdata/citus/9296/workflows/e36d1088-662a-4f60-acec-293132632c2f/jobs/131908/steps
2. https://app.circleci.com/pipelines/github/citusdata/citus/9258/workflows/37659d82-2c5b-495e-b0e7-905811e30444/jobs/131299

Failure connection leak failures:
1. https://app.circleci.com/pipelines/github/citusdata/citus/9297/workflows/c0ebc326-8c93-468f-8b70-f470bd492fb9/jobs/131920
2. https://app.circleci.com/pipelines/github/citusdata/citus/9283/workflows/9af154d0-ff96-4c5d-ae19-81faae1e0c18/jobs/131668

src/test/regress/expected/ensure_no_shared_connection_leak.out

@@ -133,17 +133,12 @@ ORDER BY 1;
 
 -- now, ensure this from the workers perspective
 -- we should only see the connection/backend that is running the command below
-SELECT
-	result, success
-FROM
-	run_command_on_workers($$select count(*) from pg_stat_activity WHERE backend_type = 'client backend';$$)
-ORDER BY 1, 2;
- result | success
----------------------------------------------------------------------
- 1      | t
- 1      | t
-(2 rows)
-
+-- TODO: Enable again once this is not failing randomly anymore
+-- SELECT
+-- 	result, success
+-- FROM
+-- 	run_command_on_workers($$select count(*) from pg_stat_activity WHERE backend_type = 'client backend';$$)
+-- ORDER BY 1, 2;
 -- in case other tests relies on these setting, reset them
 ALTER SYSTEM RESET citus.distributed_deadlock_detection_factor;
 ALTER SYSTEM RESET citus.recover_2pc_interval;

src/test/regress/sql/ensure_no_shared_connection_leak.sql

@@ -67,11 +67,12 @@ ORDER BY 1;
 
 -- now, ensure this from the workers perspective
 -- we should only see the connection/backend that is running the command below
-SELECT
-	result, success
-FROM
-	run_command_on_workers($$select count(*) from pg_stat_activity WHERE backend_type = 'client backend';$$)
-ORDER BY 1, 2;
+-- TODO: Enable again once this is not failing randomly anymore
+-- SELECT
+-- 	result, success
+-- FROM
+-- 	run_command_on_workers($$select count(*) from pg_stat_activity WHERE backend_type = 'client backend';$$)
+-- ORDER BY 1, 2;
 
 
 -- in case other tests relies on these setting, reset them