[chore][cmd/oteltestbedcol] Enable goleak (#31725)

**Description:** <Describe what has changed.>
<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
Enable `goleak` checks to help ensure no goroutines are being leaked.

**Link to tracking Issue:** <Issue number if applicable>
#30438

**Testing:** <Describe what testing was performed and which tests were
added.>
All existing tests are passing, as well as added `goleak` check.

cmd/oteltestbedcol/go.mod

@@ -47,6 +47,7 @@ require (
 	go.opentelemetry.io/collector/processor/memorylimiterprocessor v0.96.1-0.20240306115632-b2693620eff6
 	go.opentelemetry.io/collector/receiver v0.96.1-0.20240306115632-b2693620eff6
 	go.opentelemetry.io/collector/receiver/otlpreceiver v0.96.1-0.20240306115632-b2693620eff6
+	go.uber.org/goleak v1.3.0
 	golang.org/x/sys v0.18.0
 )
 

cmd/oteltestbedcol/package_test.go

@@ -0,0 +1,14 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package main
+
+import (
+	"testing"
+
+	"go.uber.org/goleak"
+)
+
+func TestMain(m *testing.M) {
+	goleak.VerifyTestMain(m, goleak.IgnoreTopFunction("go.opencensus.io/stats/view.(*worker).start"))
+}