use slash syntax instead of deprecated `in`
use slash syntax instead of deprecated `in`

- https://github.com/sbt/sbt/commit/e6fec6b1db5f212a74bf5e3766b9b70f2d983f24
- https://www.scala-sbt.org/1.x/docs/Migrating-from-sbt-013x.html#slash
septeni-original/sbt-dao-generator