build: migrate to mill 0.12.5

Signed-off-by: unlsycn <[email protected]>

.mill-version

@@ -1 +1 @@
-0.11.8
+0.12.5

benchmark/package.mill

@@ -0,0 +1,16 @@
+package build.benchmark
+
+import mill._
+import mill.scalalib._
+import mill.scalalib.scalafmt._
+import $ivy.`com.lihaoyi::mill-contrib-jmh:`
+import mill.contrib.jmh.JmhModule
+
+import build._
+
+object `package` extends RootModule with ScalaModule with JmhModule with ScalafmtModule {
+  def scalaVersion = v.scalaVersion
+  def jmhCoreVersion = v.jmhVersion
+
+  override def moduleDeps = Seq(chisel(v.scalaVersion))
+}