Upgrade to sbt 1.3.8 from 1.3.6.

* sbt/sbt#5352 was fixed in 1.3.7, hence
  the change in the comment about supershell.
* sbt/sbt#5224 was fixed in 1.3.8, which
  fixes the build on Windows.

Author: sjrd

community-build/test/scala/dotty/communitybuild/CommunityBuildTest.scala

@@ -106,7 +106,7 @@ final case class SbtCommunityProject(
       case Some(ivyHome) => List(s"-Dsbt.ivy.home=$ivyHome")
       case _ => Nil
     extraSbtArgs ++ sbtProps ++ List(
-      "-sbt-version", "1.3.6",
+      "-sbt-version", "1.3.8",
       s"--addPluginSbtFile=$sbtPluginFilePath")
 
 object projects:

project/Build.scala

@@ -196,9 +196,7 @@ object Build {
       state
     },
 
-    // Turn off the sbt supershell because it can mangle the output of some tasks
-    // (see https://github.com/sbt/sbt/issues/5122, https://github.com/sbt/sbt/issues/5352)
-    // and in general I find it more distracting than helpful anyway.
+    // I find supershell more distracting than helpful
     useSuperShell := false,
 
     // Credentials to release to Sonatype

project/build.properties

@@ -1 +1 @@
-sbt.version=1.3.6
+sbt.version=1.3.8