Fix layout of released SDK archives, restore top-level directory scala3-{{ scala-version }}

Author: WojciechMazur

.github/workflows/ci.yaml

@@ -789,19 +789,16 @@ jobs:
             distDir="$3"
 
             # Build binaries
-            ./project/scripts/sbt "${sbtProject}/Universal/stage"
+            ./project/scripts/sbt "all ${sbtProject}/Universal/packageBin ${sbtProject}/Universal/packageZipTarball"
 
             outputPath="${distDir}/target/universal/stage"
             artifactName="scala3-${{ env.RELEASE_TAG }}${distroSuffix}"
             zipArchive="${artifactName}.zip"
             tarGzArchive="${artifactName}.tar.gz"
 
-            cwd=$(pwd)
-            (cd $outputPath && zip -r ${zipArchive} . && mv ${zipArchive} "${cwd}/")
-            tar -czf ${tarGzArchive} -C "$outputPath" .
-
             # Caluclate SHA for each of archive files
             for file in "${zipArchive}" "${tarGzArchive}"; do
+              mv $outputPath/$file $file
               sha256sum "${file}" > "${file}.sha256"
             done
           }

project/Build.scala

@@ -2193,7 +2193,14 @@ object Build {
     // ========
     Universal / stage := (Universal / stage).dependsOn(republish).value,
     Universal / packageBin := (Universal / packageBin).dependsOn(republish).value,
-    Universal / packageZipTarball := (Universal / packageZipTarball).dependsOn(republish).value,
+    Universal / packageZipTarball := (Universal / packageZipTarball).dependsOn(republish)
+      .map { archiveFile =>
+        // Rename .tgz to .tar.gz for consistency with previous versions
+        val renamedFile = archiveFile.getParentFile() / archiveFile.getName.replaceAll("\\.tgz$", ".tar.gz")
+        IO.move(archiveFile, renamedFile)
+        renamedFile
+      }
+      .value,
     // ========
     Universal / mappings ++= directory(dist.base / "bin"),
     Universal / mappings ++= directory(republishRepo.value / "maven2"),