Disable ticker in unit tests (#3572)

Currently the github actions UI for the unit test jobs take forever
(~minutes) to load due to volume of logs. Ideally github actions should
be able to deal with it, but until then we can reduce the quantity of
logs

Author: lihaoyi

testkit/src/mill/testkit/UnitTester.scala

@@ -68,7 +68,7 @@ class UnitTester(
 
   object logger extends mill.util.PrintLogger(
         colored = true,
-        enableTicker = true,
+        enableTicker = false,
         mill.util.Colors.Default.info,
         mill.util.Colors.Default.error,
         new SystemStreams(out = outStream, err = errStream, in = inStream),