interfaces: mark `completelocalrepository` as a Protocol class

This is just for completeness, since everything else in here is explicitly
marked.  The *.pyi file generated for this module is unchanged, because this
class currently has no methods or attrs of its own (other than `__doc__`).

With this, the odyssey of converting the zope interfaces to Protocol classes is
complete.  There's a little bit of mopping up in making sure the previously
converted Protocols use `@abc.abstractmethod` where appropriate, but that can be
deferred for now.

mercurial/interfaces/repository.py

@@ -2233,7 +2233,9 class ilocalrepositorymain(Protocol):
 
 
 class completelocalrepository(
-    ilocalrepositorymain, ilocalrepositoryfilestorage
+    ilocalrepositorymain,
+    ilocalrepositoryfilestorage,
+    Protocol,
 ):
     """Complete interface for a local repository."""