chore: bump mill version to 1.0.6

Author: hamzaremmal

.mill-version

@@ -1 +1 @@
-1.0.0-RC1
+1.0.6

build.mill

@@ -5,7 +5,7 @@ package build
 // imports
 import mill._, scalalib._, scalanativelib._, publish._
 import com.github.lolgab.mill.mima._
-import mill.main.VcsVersion
+import mill.util.VcsVersion
 
 val communityBuildDottyVersion = sys.props.get("dottyVersion").toList