Update build.mill

Author: lihaoyi

build.mill

@@ -1,11 +1,12 @@
+//| mill-version: 1.0.0-RC3
 //| mvnDeps:
-//| - com.github.lolgab::mill-mima_mill1.0.0-RC1:0.2.0-M1
+//| - com.github.lolgab::mill-mima_mill1.0.0-RC3:0.2.0-M4
 package build
 
 // imports
 import mill._, scalalib._, scalanativelib._, publish._
 import com.github.lolgab.mill.mima._
-import mill.main.VcsVersion
+import mill.vcs.VcsVersion
 
 val communityBuildDottyVersion = sys.props.get("dottyVersion").toList