Duplicate identifier warning incorrect

## Description

For the file https://github.com/jupyterhub/team-compass/blob/cbed9d2ab7cd65e939e318083ae12d4375964a17/docs/meetings/hpc/index.md, Jupyter Book / MyST reports

```
⚠️  meetings/hpc/index.md Duplicate identifier in project "monthly-archive-hpc"
   In files: meetings/hpc/index.md, meetings/hpc/index.md
```