localrepo: eliminate requirements class variable (API) Localrepo's requirements class variable was introduced in b090601a80d1 to make requirements modifiable by extensions. A main access point, _baserequirements, still exists, but this change undoes making the class variable to begin with. Without this simplification, there is a class variable with a default value that is only copied, but never directly used. This behavior is moved directly into the _baserequirements function.