[ST] Remove checks for Kafka version higher than 3.7.0 once 3.6.x versions are removed

[im-konge]

Currently, there are few places where we are checking if the Kafka version is >= 3.7.0 (to skip test or to change some values).
Once the Kafka version 3.6.x support is removed, we should also remove these checks.

(In order to remove all checks, search for the link to this issue)