upgrade dependencies

Author: mbostock

package.json

@@ -29,7 +29,7 @@
     "test:lint": "eslint src test public"
   },
   "dependencies": {
-    "@observablehq/runtime": "^5.9.3",
+    "@observablehq/runtime": "^5.9.4",
     "acorn": "^8.10.0",
     "acorn-walk": "^8.2.0",
     "fast-array-diff": "^1.1.0",