bump: scala-library 2.13.13 (was 2.13.12) (#609)

Author: scala-steward

build.sbt

@@ -66,7 +66,7 @@ lazy val core = project
   .in(file("core"))
   .settings(
     name               := "paradox",
-    crossScalaVersions := Seq(scalaVersion.value, "2.13.12"),
+    crossScalaVersions := Seq(scalaVersion.value, "2.13.13"),
     libraryDependencies ++= Library.pegdown,
     libraryDependencies ++= Seq(
       Library.st4,