Update React version to exact 19.0.0 in package.json

Author: AbanoubGhadban

spec/dummy/package.json

@@ -47,8 +47,8 @@
     "postcss": "^8.4.31",
     "postcss-loader": "^7.1.0",
     "prop-types": "^15.7.2",
-    "react": "^19.0.0",
-    "react-dom": "^19.0.0",
+    "react": "19.0.0",
+    "react-dom": "19.0.0",
     "react-error-boundary": "^4.1.2",
     "react-helmet": "^6.0.0-beta.2",
     "react-on-rails": "git+https://github.com/shakacode/react_on_rails.git#abanoubghadban/pro362-add-support-for-RSC",