interfaces: drop the conditional import of the vendored `zope` packages

The real `zope` code was only used when enabled by a test, and the decorators
turned into no-ops at runtime.  Now that the test is disabled, unconditionally
use the no-op decorators and stop importing the code.  This module can go away
once the `mercurial.interfaces.repository` interfaces are converted to Protocol
classes, but the vendored code can be deleted in the meantime.

mercurial/interfaces/util.py

@@ -11,15 +11,7
 
 from __future__ import annotations
 
-from .. import encoding
-
-if encoding.environ.get(b'HGREALINTERFACES'):
-    from ..thirdparty.zope import interface as zi
-
-    Attribute = zi.Attribute
-    Interface = zi.Interface
-    implementer = zi.implementer
-else:
+if True:
 
     class Attribute:
         def __init__(self, __name__, __doc__=b''):