rcutil: drop the `defaultrcpath()` method (API)

The resource based code can service py2, py3 and an oxidized executable, so
there's no reason to leave this around.  It was flagged as an API change when it
was introduced, so flagging it again.

Differential Revision: https://phab.mercurial-scm.org/D7777

mercurial/rcutil.py

@@ -61,12 +61,6 b' def envrcitems(env=None):'
     return result
 
 
-def defaultrcpath():
-    '''return rc paths in defaultrc'''
-    defaultpath = os.path.join(resourceutil.datapath, b'defaultrc')
-    return _expandrcpath(defaultpath)
-
-
 def default_rc_resources():
     """return rc resource IDs in defaultrc"""
     rsrcs = resourceutil.contents(b'mercurial.defaultrc')
@@ -107,7 +101,7 b' def rccomponents():'
         normpaths = lambda paths: [
             (b'path', os.path.normpath(p)) for p in paths
         ]
-        _rccomponents.extend(normpaths(defaultrcpath() + systemrcpath()))
+        _rccomponents.extend(normpaths(systemrcpath()))
         _rccomponents.append(envrc)
         _rccomponents.extend(normpaths(userrcpath()))
     return _rccomponents

tests/test-config-env.py

@@ -36,7 +36,6 b' def userrcpath():'
     return [join(b'userrc')]
 
 
-extensions.wrapfunction(rcutil, 'defaultrcpath', lambda orig: [])
 extensions.wrapfunction(rcutil, 'default_rc_resources', lambda orig: [])
 
 rcutil.systemrcpath = systemrcpath