Update cats-effect, cats-effect-testkit to 3.6.3 in series/1.x

Author: typelevel-steward[bot]

build.sbt

@@ -26,7 +26,7 @@ ThisBuild / tlVersionIntroduced := Map("3" -> "1.1.1")
 
 ThisBuild / tlCiReleaseBranches := Seq("series/1.x")
 
-val CatsEffectVersion = "3.6.2"
+val CatsEffectVersion = "3.6.3"
 val ScalaTestVersion = "3.2.18"
 
 lazy val root = tlCrossRootProject