git: correct some signature mismatches between dirstate and the Protocol class

These were flagged by PyCharm when subclassing the Protocol class.  Note that
both `is_changing_xxx` were only flagged when the Protocol class used a plain
field, as mentioned in the previous commit.  After converting those attrs in the
Protocol class to @property to match the regular dirstate class, it stopped
flagging these.  But I don't think that makes sense- `@property` should look
like an attribute to the outside world, not a callable.

hgext/git/dirstate.py

@@ -243,7 +243,7 b' class gitdirstate:'
             return DirstateItem()
         return entry
 
-    def normalize(self, path):
+    def normalize(self, path, isknown=False, ignoremissing=False):
         normed = util.normcase(path)
         assert normed == path, b"TODO handling of case folding: %s != %s" % (
             normed,
@@ -262,11 +262,13 b' class gitdirstate:'
     # # TODO what the heck is this
     _filecache = set()
 
+    @property
     def is_changing_parents(self):
         # TODO: we need to implement the context manager bits and
         # correctly stage/revert index edits.
         return False
 
+    @property
     def is_changing_any(self):
         # TODO: we need to implement the context manager bits and
         # correctly stage/revert index edits.