Describe the enhancement
Many people would like to cache some "system" directory but are not able to since it is the runner user who make the tar.
Adding a sudo option who could be used later by actions/cache will solve the problem

Code Snippet
There are many demands about it :
actions/cache#181 (comment)
actions/cache#133 (comment)
actions/cache#155
actions/cache#324 (comment)
actions/cache#629