Add goleak check in pkg/cassandra/gocql/testutils (#5304)

## Which problem is this PR solving?
- Part of #5006

## Description of the changes
- added goleak check in `pkg/cassandra/gocql/testutils`

## How was this change tested?
- ``make test ``

## Checklist
- [x] I have read
https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
- [x] I have signed all commits
- [x] I have added unit tests for the new functionality
- [x] I have run lint and test steps successfully
  - for `jaeger`: `make lint test`
  - for `jaeger-ui`: `yarn lint` and `yarn test`

---------

Signed-off-by: danish siddiqui <[email protected]>

pkg/cassandra/gocql/testutils/udt_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/gocql/gocql"
 
 	"github.com/jaegertracing/jaeger/pkg/cassandra/gocql/testutils"
+	goleakTestutils "github.com/jaegertracing/jaeger/pkg/testutils"
 )
 
 // CustomUDT is a custom type that implements gocql.UDTMarshaler and gocql.UDTUnmarshaler interfaces.
@@ -79,3 +80,7 @@ func TestUDTTestCase(t *testing.T) {
 
 	testCase.Run(t)
 }
+
+func TestMain(m *testing.M) {
+	goleakTestutils.VerifyGoLeaks(m)
+}