SendN sends events in a common t.Run (#2421)
SendN sends events in a common t.Run (#2421)

Running them in separate t.Run functions causes issues such as the
following one because events might be sent after the t.Run ends since
they run in separate go routines in background:

panic: Fail in goroutine after
TestKafkaSinkV1Alpha1AuthPlaintext/1/send_event_0 has completed

goroutine 6809 [running]:
testing.(*common).Fail(0xc002b5c340)
	/root/.gvm/gos/go1.17.8/src/testing/testing.go:710 +0x1b4
testing.(*common).FailNow(0xc002b5c340)
	/root/.gvm/gos/go1.17.8/src/testing/testing.go:732 +0x2f
testing.(*common).Fatalf(0xc00437a000, {0x2b71c16, 0x22}, {0xc004acfbd8,
0x3, 0x3})
	/root/.gvm/gos/go1.17.8/src/testing/testing.go:830 +0x85
knative.dev/eventing/test/lib.(*Client).SendEvent(0xc0035c2d20,
{0x3137bb0, 0xc0000e0008}, {0xc004096420, 0x11}, {0xc00437a000, 0x56},
{{0x319fac0, 0xc0031adce0}, {0xc0040af158, ...}, ...}, ...)

/root/.gvm/pkgsets/go1.17.8/global/src/knative.dev/eventing-kafka-broker/vendor/knative.dev/eventing/test/lib/send_event.go:63
+0x525
knative.dev/eventing/test/lib.(*Client).SendEventToAddressable(0xc0035c2d20,
{0x3137bb0, 0xc0000e0008}, {0xc004096420, 0x11}, {0x2b4f151, 0xa},
0xc00374f2a0, {{0x319fac0, 0xc0031adce0}, ...}, ...)

/root/.gvm/pkgsets/go1.17.8/global/src/knative.dev/eventing-kafka-broker/vendor/knative.dev/eventing/test/lib/send_event.go:45
+0x1fb
knative.dev/eventing-kafka-broker/test/pkg/addressable.SendN.func1.1.1(0x0)

/root/.gvm/pkgsets/go1.17.8/global/src/knative.dev/eventing-kafka-broker/test/pkg/addressable/send.go:72
+0x5cd
knative-sandbox/eventing-kafka-broker,knative-sandbox/eventing-kafka-broker,knative-sandbox/eventing-kafka-broker