Upgrade actions and pkgdown configuration

[dieghernan]

I noticed that your actions fails because they are out-of-date. This PR update the actions to the latest versions (adapted from https://github.com/rOpenGov/giscoR/tree/main/.github/workflows).

I also updated the pkgdown file as they were several articles that have been removed, as well as new function added but not listed (is.survey_df()) that makes the workflow fail.

[antaldaniel]

Hi @dieghernan, thank you for this pull request. This package needs a more thorough upgrade, and the problem that caused the problem in the pkgdown is well spotted. I started to move important functionality out of the package to a more general dataset pacakge, but than just caught a bad flu and did not finish with the cleanup. But the cleanup of the actions is really welcome.

I'll approve now the changes but if I have questions about something I may come back to you!

[antaldaniel]

Thank you for this cleanup. I am in the middle of a thorough rewrite of some part of the package, and the pgkdown was not actualised, but cleaning up the workflows was really welcome. I am not working in the next few days on this package, and therefore I cannot review all changes now, but since your changes do not concern the source code I will approve the pull request.