refactor: rename experimental.ppr to experimental.cacheComponents
BREAKING CHANGE: The `experimental.ppr` configuration option has been renamed to `experimental.cacheComponents`.
This change renames the Partial Prerendering (PPR) feature to Cache Components throughout the codebase:
- Remove `experimental.ppr` config option
- Replace with `experimental.cacheComponents`
- Update all PPR-related code to use cache components terminology
- Remove PPR-specific CI test jobs
- Update error messages and documentation
Migration:
Replace `experimental.ppr` with `experimental.cacheComponents` in your next.config.js