Remove carat (^) from wagmi versioning.

This is because it updates from 2.12.7 --> 2.15.6 which causes
breaking changes in viem. There is a type mismatch that gets caused, even though
they're minor versions and ought not cause breaking changes.

Note that currently
1. viem is pinned to only 1 fixed version
2. same now for wagmi
3. react-components package depends on ccip-js and since it has carat it will update on install to next patch.

Author: zeuslawyer

examples/nextjs/package.json

@@ -21,7 +21,7 @@
     "react-dom": "18",
     "typescript": "^5",
     "viem": "2.21.25",
-    "wagmi": "^2.12.7"
+    "wagmi": "2.12.7"
   },
   "devDependencies": {
     "@types/node": "^20",

packages/ccip-js/package.json

@@ -50,6 +50,6 @@
     "mocha": "^11.1.0",
     "ts-jest": "^29.2.5",
     "typescript": "^5.8.2",
-    "viem": "^2.31.3"
+    "viem": "2.21.25"
   }
 }

packages/ccip-react-components/package.json

@@ -48,8 +48,8 @@
     "tailwind-merge": "^2.3.0",
     "tailwindcss-animate": "^1.0.7",
     "typescript": "^5.2.2",
-    "viem": "^2.31.3",
-    "wagmi": "^2.12.7",
+    "viem": "2.21.25",
+    "wagmi": "2.12.7",
     "zod": "^3.23.8"
   },
   "devDependencies": {