Add warning or delete <func-root>/.s2i for older functions #3452
Description
created as a follow-up based on #3436 (comment)
Add a warning when deploying via s2i builder after the PR mentioned above is merged (since its changing the s2i scaffolding paths).
Alternatively it might also straight up delete the .s2i/ directory. Or maybe prompting for the deletion with a note like "hey this is old s2i scaffolding, you are using ... its not needed anymore, can I proceed deleting this?" -- that way the user does not have much to deal with... something to consider.