Merge pull request #224 from scala-steward/update/scala-library-2.13.15

Update scala-library to 2.13.15

Author: magro

build.sbt

@@ -15,7 +15,7 @@ licenses := Seq("Apache-2.0" -> url("http://www.apache.org/licenses/LICENSE-2.0.
 scalaVersion := "3.4.3"
 
 // Remember: also update scala versions in .travis.yml!
-crossScalaVersions := Seq("2.12.20", "2.13.14", "3.4.3")
+crossScalaVersions := Seq("2.12.20", "2.13.15", "3.4.3")
 
 scalacOptions ++= Seq(
   "-unchecked",