Remove redundant example code for cacheLife docs (#86043)
Remove redundant example code for overriding cache profiles.
## For Contributors
### Improving Documentation
- Run `pnpm prettier-fix` to fix formatting issues before opening the
PR. ✅ (no changes)
- Read the Docs Contribution Guide to ensure your contribution follows
the docs guidelines:
https://nextjs.org/docs/community/contribution-guide ✅
### What?
Remove a redundant example in the `cacheLife` docs.
### Why?
Because the redundant example is confusing.
### How?
Closes NEXT-
Fixes #
-->
