Update scala3-library to 3.8.1

Author: scala-steward-bot

build.sbt

@@ -3,7 +3,7 @@ lazy val `sbt-release` = project in file(".")
 organization := "com.github.sbt"
 name := "sbt-release"
 
-crossScalaVersions += "3.7.4"
+crossScalaVersions += "3.8.1"
 
 pluginCrossBuild / sbtVersion := {
   scalaBinaryVersion.value match {