Update action render_page.yml

[GeertvanGeest]

After the update of MkDocs, you will need to install setuptools to enable the bibtex plugin. Due to security reasons, it is not straightforward to make workflows part of the template sync. In order to make dependency updates part of the template sync in the future, I have specified the dependencies in a requirements.txt file.

Please follow the steps below to fix the issue:

• Update .github/workflows/render_page.yml. You can do this by copy-pasting the content of https://github.com/elixir-europe-training/ELIXIR-TrP-LessonTemplate-MkDocs/blob/main/.github/workflows/render_page.yml.
• Manually run the template sync action by clicking: Actions > .github/workflows/template_sync.yml > Run workflow > Run workflow.
• Accept the pull request created by the action (wait until the action has completed and find it at Pull requests)

Please mark this issue as complete if you have (already) fixed this.