Install quarto before installing R dependencies

We have a Run quarto-dev/quarto-actions/setup@v2 step with the version specified. However, the r-lib/actions/setup-r-dependencies@v2 step in the workflow was indirectly causing another copy of Run quarto-dev/quarto-actions/setup@v2 to run, but without a version specified. This installation failed because the system doesn't want to downgrade the .deb package.