chore(deps): bump aws-cdk-lib in /examples/servers/book-search

Bumps [aws-cdk-lib](https://github.com/aws/aws-cdk) from 2.208.0 to 2.212.0.
- [Release notes](https://github.com/aws/aws-cdk/releases)
- [Changelog](https://github.com/aws/aws-cdk/blob/main/CHANGELOG.v2.alpha.md)
- [Commits](aws/aws-cdk@v2.208.0...v2.212.0)

---
updated-dependencies:
- dependency-name: aws-cdk-lib
  dependency-version: 2.212.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

examples/servers/book-search/requirements.txt

@@ -1,4 +1,4 @@
-aws-cdk-lib==2.208.0
+aws-cdk-lib==2.212.0
 aws-cdk.aws-lambda-python-alpha==2.212.0a0
 constructs>=10.0.0,<11.0.0
 cdk-nag==2.37.8