fix(deps): Add PostgreSQL module for Flyway 11 compatibility

Flyway 11 requires database-specific modules to be explicitly included.
Added flyway-database-postgresql dependency to ensure PostgreSQL tests work correctly.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: j5ik2o

build.sbt

@@ -156,6 +156,7 @@ val `docker-controller-scala-flyway` = (project in file("docker-controller-scala
     libraryDependencies ++= Seq(
       "org.flywaydb"      % "flyway-core"  % "11.12.0",
       "org.flywaydb"      % "flyway-mysql" % "11.12.0",
+      "org.flywaydb"      % "flyway-database-postgresql" % "11.12.0",
       scalatest.scalatest % Test,
       logback.classic     % Test
     )