[test] Activity has types and supports react-server (#78196)

Backport of #78066 to 15.3.x

---------

Co-authored-by: Sebastian "Sebbie" Silbermann <sebastian.silbermann@vercel.com>

Author: styfle

package.json

@@ -131,8 +131,8 @@
     "@types/jest": "29.5.5",
     "@types/node": "20.17.6",
     "@types/node-fetch": "2.6.1",
-    "@types/react": "19.0.8",
-    "@types/react-dom": "19.0.3",
+    "@types/react": "19.1.1",
+    "@types/react-dom": "19.1.2",
     "@types/relay-runtime": "14.1.13",
     "@types/string-hash": "1.1.1",
     "@types/trusted-types": "2.0.3",
@@ -288,8 +288,8 @@
       "@babel/parser": "7.22.5",
       "@babel/types": "7.22.5",
       "@babel/traverse": "7.22.5",
-      "@types/react": "19.0.8",
-      "@types/react-dom": "19.0.3",
+      "@types/react": "^19.1.1",
+      "@types/react-dom": "19.1.2",
       "jest-snapshot": "30.0.0-alpha.6",
       "react": "19.2.0-canary-3fbfb9ba-20250409",
       "react-dom": "19.2.0-canary-3fbfb9ba-20250409",