Update dependency react to v19

Author: brianclemens

package.json

@@ -24,7 +24,7 @@
     "gatsby-transformer-sharp": "^5.13.1",
     "postcss": "^8.4.38",
     "prop-types": "^15.8.1",
-    "react": "^18.3.1",
+    "react": "^19.0.0",
     "react-dom": "^18.3.1",
     "react-helmet": "^6.1.0"
   },