fix: pin quarto version

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Description

There is a breaking change with quarto v1.7.29 which workflows recently started installing. These are causing doc-build failures.

See https://github.com/ansys/pymapdl/actions/runs/14712614347/job/41288570436 for example. Also see https://github.com/ansys/actions/pull/791

Checklist

• [x] I have visited and read Develop PyMAPDL.
• [x] I have followed the PyMAPDL coding style guidelines.
• [x] I have reviewed my changes before submitting this pull request.
• [x] I have assigned this PR to myself.
• [x] I have made sure that the title of my PR follows Commit naming conventions (e.g. feat: adding new MAPDL command)