sbt-dotty: fix extension upgrade on Windows

When using --install-extension and an upgraded version of the extension
exists online, the user normally gets a prompt to accept or reject the
upgrade. Using --force we bypass this prompt and we also fix an issue
with Windows where the prompt does not appear and we get the error
"Unknown stdin file type" instead.

Author: smarter

sbt-dotty/src/dotty/tools/sbtplugin/DottyIDEPlugin.scala

@@ -197,7 +197,7 @@ object DottyIDEPlugin extends AutoPlugin {
    */
   def installCodeExtension(codeCmd: Seq[String], name: String): Unit = {
     try {
-      runProcess(codeCmd ++ Seq("--install-extension", name), wait = true)
+      runProcess(codeCmd ++ Seq("--force", "--install-extension", name), wait = true)
     } catch {
       case e: Exception =>
         var alreadyInstalled: Boolean = false