Update sbt to 2.0.0-RC4

Author: scala-text-bot[bot]

build.sbt

@@ -26,7 +26,7 @@ libraryDependencySchemes ++= Seq(
 ).map("org.scala-sbt" % _ % "always")
 
 libraryDependencies ++= Seq(
-  "org.scala-sbt" % "sbt" % "2.0.0-RC3",
+  "org.scala-sbt" % "sbt" % "2.0.0-RC4",
   "org.mockito" % "mockito-core" % "5.19.0",
   "org.scalacheck" %% "scalacheck" % "1.18.1",
   "org.scalatest" %% "scalatest-flatspec" % "3.2.19", // mdocで使うので、テストライブラリだが、わざとcompileスコープ