Delete migration module and migration scripts

build.sbt

@@ -4,7 +4,7 @@ lazy val `pekko-persistence-postgres` = project
   .in(file("."))
   .enablePlugins(ScalaUnidocPlugin)
   .disablePlugins(MimaPlugin)
-  .aggregate(core, migration)
+  .aggregate(core)
   .settings(publish / skip := true)
 
 lazy val core = project
@@ -15,15 +15,6 @@ lazy val core = project
     libraryDependencies ++= Dependencies.Libraries,
     mimaBinaryIssueFilters ++= Seq())
 
-lazy val migration = project
-  .in(file("migration"))
-  .disablePlugins(MimaPlugin)
-  .settings(
-    name := "pekko-persistence-postgres-migration",
-    libraryDependencies ++= Dependencies.Migration,
-    Test / parallelExecution := false)
-  .dependsOn(core)
-
 TaskKey[Unit]("verifyCodeFmt") := {
   scalafmtCheckAll.all(ScopeFilter(inAnyProject)).result.value.toEither.left.foreach { _ =>
     throw new MessageOnlyException(