MINOR: Fix 3.7 build failure by removing a superfluous empty snapshot…

… file (apache#15076)

3.7 builds are failing with:
```
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':rat'.
> A failure occurred while executing org.nosphere.apache.rat.RatWork
   > Apache Rat audit failure - 1 unapproved license
     	See file:///home/jenkins/jenkins-agent/workspace/Kafka_kafka_3.7/build/rat/index.html
```
Upon a local run, I see that it's failing because a file is missing a license.

I notice that this file was erroneously introduced with the 3.7 cherry-pick of 380eb62, so this patch removes it