use English locale in toLowerCase() instead of default

The default depends on the target machine and may not produce consistent
results.

build.sbt

@@ -63,7 +63,7 @@ assembly / assemblyJarName := s"${name.value}-cli.jar"
 //
 assembly / assemblyMergeStrategy := {
   case p0 @ PathList("META-INF", xs @ _*) =>
-    (xs.map(_.toLowerCase)) match {
+    (xs.map(_.toLowerCase(java.util.Locale.ENGLISH))) match {
       case p1 if p1.last == "module-info.class" => MergeStrategy.discard
       case p1 if p1.last == "javax.inject.named" => MergeStrategy.filterDistinctLines
       case p1 if p1.last == "io.netty.versions.properties" => MergeStrategy.filterDistinctLines

src/main/scala/sc4pac/Constants.scala

@@ -92,5 +92,5 @@ object Constants {
     true
   }
 
-  def isDll(path: os.Path): Boolean = path.last.toLowerCase.endsWith(".dll")
+  def isDll(path: os.Path): Boolean = path.last.toLowerCase(java.util.Locale.ENGLISH).endsWith(".dll")
 }

src/main/scala/sc4pac/Prompt.scala

@@ -50,7 +50,7 @@ object Prompt {
     } yield {
       if (input.isEmpty) default
       else {
-        val matches: Seq[String] = options.filter(_.toLowerCase().startsWith(input.toLowerCase()))
+        val matches: Seq[String] = options.filter(_.toLowerCase(java.util.Locale.ENGLISH).startsWith(input.toLowerCase(java.util.Locale.ENGLISH)))
         matches match {
           case Seq(unique) => Some(unique)
           case _ => None

src/main/scala/sc4pac/extractor.scala

@@ -13,7 +13,7 @@ import sc4pac.error.ExtractionFailed
 object Extractor {
 
   def acceptNestedArchive(p: os.BasePath) = {
-    val name = p.last.toLowerCase
+    val name = p.last.toLowerCase(java.util.Locale.ENGLISH)
     name.endsWith(".jar") || name.endsWith(".zip") || name.endsWith(".7z") || name.endsWith(".exe")
   }
 
@@ -47,7 +47,7 @@ object Extractor {
 
   private object WrappedArchive {
     def apply(file: java.io.File, fallbackFilename: Option[String], stagingRoot: os.Path, logger: Logger, hints: Option[JD.ArchiveType]): WrappedArchive[?] = {
-      val lcNames: Seq[String] = Seq(file.getName.toLowerCase) ++ fallbackFilename.map(_.toLowerCase)
+      val lcNames: Seq[String] = Seq(file.getName.toLowerCase(java.util.Locale.ENGLISH)) ++ fallbackFilename.map(_.toLowerCase(java.util.Locale.ENGLISH))
       if (lcNames.exists(_.endsWith(".exe")) && hints.exists(_.format.equalsIgnoreCase(JD.ArchiveType.clickteamFormat))) {
         /* Clickteam installer */
         val tempExtractionDir = os.temp.dir(stagingRoot, prefix = "exe", deleteOnExit = false)  // the parent stagingRoot is already temporary and will be deleted