Remove existentials and higherKinds features for dotty builds

Author: mbovel

bench/profiles/projects.yml

@@ -26,7 +26,7 @@ charts:
 
 scripts:
     dotty:
-        - measure -feature -deprecation -unchecked -Xfatal-warnings -encoding UTF8 -language:existentials,higherKinds,implicitConversions -Yexplicit-nulls -with-compiler $(find $PROG_HOME/dotty/compiler/src/dotty -name *.scala -o -name *.java)
+        - measure -feature -deprecation -unchecked -Xfatal-warnings -encoding UTF8 -language:implicitConversions -Yexplicit-nulls -with-compiler $(find $PROG_HOME/dotty/compiler/src/dotty -name *.scala -o -name *.java)
 
     re2s:
         - measure $(find $PROG_HOME/tests/re2s/src -name *.scala)

project/Build.scala

@@ -171,7 +171,7 @@ object Build {
       "-unchecked",
       "-Xfatal-warnings",
       "-encoding", "UTF8",
-      "-language:existentials,higherKinds,implicitConversions"
+      "-language:implicitConversions"
     ),
 
     (Compile / compile / javacOptions) ++= Seq("-Xlint:unchecked", "-Xlint:deprecation"),