Remove Spring Boot Pulsar 4 smoke test

[philwebb]

We should be able to remove it in 3.5.x

[thecooldrop]

I would like to work on this issue. The change seems to be quite trivial, but I would also be interessted in why this needs to be done?

[philwebb]

Thanks for the offer @thecooldrop, but this was blocked until the Pulsar upgrade so we couldn't accept contributions.