Refactor Scala client, server Github workflow for testing #6

Job	Run time
Build sbt/Scala (samples/client/petstore/scala-pekko)	1m 1s
Build sbt/Scala (samples/client/petstore/scala-sttp4-jsoniter)	1m 0s
Build sbt/Scala (samples/client/petstore/scala-http4s)	1m 3s
Build sbt/Scala (samples/client/petstore/scalaz)	1m 4s
Build sbt/Scala (samples/client/petstore/scala-akka)	1m 23s
Build sbt/Scala (samples/client/petstore/scala-sttp4)	48s
Build sbt/Scala (samples/client/petstore/scala-sttp-circe)	56s
Build sbt/Scala (samples/client/petstore/scala-sttp)	56s
	8m 11s

Provide feedback