Move label data to a data file so multiple scripts can reference them

script/label_data.json

@@ -0,0 +1,13 @@
+{
+  "core_labels": [
+    "defect",
+    "design",
+    "documentation",
+    "duplicate",
+    "enhancement",
+    "panic / crash",
+    "support"
+  ],
+  "additional_labels": ["ai", "linux", "vim", "windows"],
+  "ignored_label": "ignore top-ranking issues"
+}