Prepare site for React 19.3 release (#8649)

Author: samselikoff

package.json

@@ -93,7 +93,7 @@
     "postcss-flexbugs-fixes": "4.2.1",
     "postcss-preset-env": "^6.7.0",
     "prettier": "^2.5.1",
-    "react-server-dom-webpack": "^19.2.4",
+    "react-server-dom-webpack": "^19.3.0",
     "reading-time": "^1.2.0",
     "remark": "^12.0.1",
     "remark-external-links": "^7.0.0",