Updated to `Dart 2.19.6`

packages/dart/2.19.6/build.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+curl -L "https://storage.googleapis.com/dart-archive/channels/stable/release/2.19.6/sdk/dartsdk-linux-x64-release.zip" -o dart.zip
+
+unzip dart.zip
+rm dart.zip
+
+cp -r dart-sdk/* .
+rm -rf dart-sdk
+
+chmod -R +rx bin

packages/dart/2.19.6/environment

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+# Put 'export' statements here for environment variables
+export PATH=$PWD/bin:$PATH

packages/dart/2.19.6/metadata.json

@@ -0,0 +1,5 @@
+{
+    "language": "dart",
+    "version": "2.19.6",
+    "aliases": []
+}

packages/dart/2.19.6/run

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+# Put instructions to run the runtime
+dart run "$@"

packages/dart/2.19.6/test.dart

@@ -0,0 +1,3 @@
+void main() {
+  print('OK');
+}