build: add vega to devDeps and remove unused dep

Author: richadr

packages/components-react/vega-visualization-react/package.json

@@ -60,8 +60,7 @@
     "typecheck": "tsc --noEmit"
   },
   "dependencies": {
-    "@utrecht/vega-visualization-css": "workspace:*",
-    "clsx": "2.1.1"
+    "@utrecht/vega-visualization-css": "workspace:*"
   },
   "devDependencies": {
     "@testing-library/dom": "10.4.1",