Update cats-core to 2.8.0 (#663)

Author: typelevel-steward[bot]

build.sbt

@@ -26,7 +26,7 @@ ThisBuild / githubWorkflowJavaVersions := Seq(JavaSpec.temurin("8"), JavaSpec.te
 
 ThisBuild / tlVersionIntroduced := Map("3" -> "2.1.1")
 
-val catsV = "2.7.0"
+val catsV = "2.8.0"
 val catsEffectV = "3.3.14"
 val slf4jV = "1.7.36"
 val munitCatsEffectV = "1.0.7"