TestNatsChannel test is flaky

[eleftherias]

The TestNatsChannel test is inconsistently failing. Failure example: https://github.com/stacklok/minder/actions/runs/10610301617/job/29407533319 Success example: https://github.com/stacklok/minder/actions/runs/10610294403/job/29407511948

Failure reason:

  make: *** [.mk/test.mk:32: test-silent] Error 1
      natschannel_test.go:96: Got {"msg":"hello"} from out1
      natschannel_test.go:101: timeout waiting for message 2