--- re-building ‘extending.Rmd’ using rmarkdown

processing vignette 'extending.Rmd' failed with diagnostics:

Vignette re-building failed.

Build process failed

Process completed with exit code 1.

Input 'save-always' has been deprecated with message: save-always does not work as intended and will be removed in a future release. A separate `actions/cache/restore` step should be used instead. See https://github.com/actions/cache/tree/main/save#always-save-cache for more details.