Update scala-library to 2.13.18

Author: typelevel-steward[bot]

build.sbt

@@ -14,7 +14,7 @@ ThisBuild / developers := List(
 // publish website from this branch
 ThisBuild / tlSitePublishBranch := Some("main")
 
-val Scala213 = "2.13.16"
+val Scala213 = "2.13.18"
 ThisBuild / crossScalaVersions := Seq(Scala213, "3.3.6")
 ThisBuild / scalaVersion := Scala213 // the default Scala