Non-chapel code blocks get tagged with the Chapel version

When using the `chplVersion` tag, non-chapel code blocks get tagged with the Chapel version. I don't think they should.

For example

<img width="749" height="193" alt="Image" src="https://github.com/user-attachments/assets/aca712ac-4756-4d73-8e5f-9e7993fd783b" />