Allow multiple dart <script> tags in .sky files

sky/tests/modules/resources/multiple-scripts-child.sky

Index: sky/tests/modules/resources/multiple-scripts-child.sky
diff --git a/sky/tests/modules/resources/multiple-scripts-child.sky b/sky/tests/modules/resources/multiple-scripts-child.sky
new file mode 100644
index 0000000000000000000000000000000000000000..dd3e5eaac81e9b15066a69b8c65ac41f3e77560e
--- /dev/null
+++ b/sky/tests/modules/resources/multiple-scripts-child.sky
@@ -0,0 +1,18 @@
+<sky>
+<script>
+final String one = 'one';
+bool oneInit = false;
+void init() {
+    oneInit = true;
+}
+final conflict = 'one';
+</script>
+<script>
+final String two = 'two';
+bool twoInit = false;
+void init() {
+    twoInit = true;
+}
+final conflict = 'two';
+</script>
+</sky>