chore: rework logic around vtk-osmesa

[SMoraisAnsys]

Description

Updating the logic around the use of vtk on CI / doc build to leverage vtk's feature of defining an OpenGL context backend. This should avoid any issue that happens from time to time when trying to retrieve wheels from VTK's GitLab registry.

Issue linked

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Checklist

• I have tested my changes locally.
• I have added necessary documentation or updated existing documentation.
• I have followed the coding style guidelines of this project.
• I have added appropriate tests (unit, integration, system).
• I have reviewed my changes before submitting this pull request.
• I have linked the issue or issues that are solved by the PR if any.
• I have assigned this PR to myself.
• I have made sure that the title of my PR follows Conventional commits style (e.g. feat: add optical property)
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