docs: istio helm chart version used in kubernetes examples updated to v1.27.1

[dadrus]

Related issue(s)

House keeping

Checklist

• [x] I agree to follow this project's Code of Conduct.
• [x] I have read, and I am following this repository's Contributing Guidelines.
• [x] I have read the Security Policy.
• [ ] I have referenced an issue describing the bug/feature request.
• [ ] I have added tests that prove the correctness of my implementation.
• [ ] I have updated the documentation.

Description

TBD