Fix Generator

[mdedetrich]

What happened?

There is a range index issue when generating S3 bucket names for tests, i.e.

[info] - Bucket name generators generates valid bucket names according to S3Settings with virtualDotHost and prefix *** FAILED ***
[info]   IllegalArgumentException was thrown during property evaluation.
[info]     Message: requirement failed: invalid size given: -1
[info]     Occurred when passed generated values (
[info]   
[info]     )

What did you expect to happen?

For it to not fail

What else do we need to know?

There is some fencepost error that needs to be looked into at https://github.com/aiven/guardian-for-apache-kafka/blob/main/core-s3/src/test/scala/io/aiven/guardian/kafka/s3/Generators.scala