build(deps): update mill-libs-scalalib, mill-testkit from 1.1.6 to 1.1.7 (#2054)

Author: scala-steward

project/Dependencies.scala

@@ -40,7 +40,7 @@ object Dependencies {
 
     val hocon = "1.4.9"
 
-    val mill = "1.1.6"
+    val mill = "1.1.7"
 
     val mutationTestingElements = "3.8.0"