chore: fix @next -> @latest (#6623)

Closes #

## 🎯 Changes

What changes are made in this PR? Is it a feature or a bug fix?

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## ✅ Checklist

- [ ] I have followed the steps listed in the [Contributing
guide](https://github.com/trpc/trpc/blob/main/CONTRIBUTING.md).
- [ ] If necessary, I have added documentation related to the changes
made.
- [ ] I have added or updated the tests related to the changes made.


<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit

- **Chores**
- Updated dependency configurations to switch from pre-release ("@next")
versions to the latest stable releases of tRPC packages.
- **Documentation**
- Revised installation instructions across guides and examples to
reflect the use of stable dependency versions, improving clarity and
stability for users.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: KATT

package.json

@@ -33,10 +33,10 @@
   "dependencies": {
     "@prisma/client": "^5.12.1",
     "@tanstack/react-query": "^5.67.1",
-    "@trpc/client": "npm:@trpc/client@next",
-    "@trpc/next": "npm:@trpc/next@next",
-    "@trpc/react-query": "npm:@trpc/react-query@next",
-    "@trpc/server": "npm:@trpc/server@next",
+    "@trpc/client": "npm:@trpc/client",
+    "@trpc/next": "npm:@trpc/next",
+    "@trpc/react-query": "npm:@trpc/react-query",
+    "@trpc/server": "npm:@trpc/server",
     "clsx": "^2.0.0",
     "next": "^15.1.7",
     "react": "^19.0.0",