Update cats-core to 2.9.0

Author: scala-steward

build.sbt

@@ -41,7 +41,7 @@ lazy val core = crossProject(JSPlatform, JVMPlatform, NativePlatform)
     name := "diffson-core",
     libraryDependencies ++= Seq(
       "org.scala-lang.modules" %%% "scala-collection-compat" % "2.8.1",
-      "org.typelevel" %%% "cats-core" % "2.8.0",
+      "org.typelevel" %%% "cats-core" % "2.9.0",
       "org.scalatest" %%% "scalatest" % scalatestVersion % Test,
       "org.scalacheck" %%% "scalacheck" % scalacheckVersion % Test
     ),