fix: compile runners first and use node v20 in gh actions

.github/workflows/test.yml

@@ -28,7 +28,7 @@ jobs:
       - name: Set up NPM
         uses: actions/setup-node@v2
         with:
-          node-version: '21'
+          node-version: '20'
 
       - name: Build
         run: ./gradlew installDist --console=plain --warning-mode all

src/main/kotlin/Main.kt

@@ -51,7 +51,7 @@ internal suspend fun exec(path: String) {
   }
 
   // For each package, run the preparation command if it exists.
-  parser.packages.forEach { prepare(it) }
+  parser.packages.sortedBy { it.runners.size * -1 }.forEach { prepare(it) }
 
   // Start the orchestrator.
   Log.shared.debug("Invoking orchestrator.")