extensions: stop using the `pycompat.open()` shim

mercurial/extensions.py

@@ -19,9 +19,6 from .i18n import (
     _,
     gettext,
 )
-from .pycompat import (
-    open,
-)
 
 from . import (
     cmdutil,
@@ -805,7 +802,7 def _moduledoc(file):
 def _disabledhelp(path):
     '''retrieve help synopsis of a disabled extension (without importing)'''
     try:
-        with open(path, b'rb') as src:
+        with open(path, 'rb') as src:
             doc = _moduledoc(src)
     except IOError:
         return
@@ -888,7 +885,7 def _disabledcmdtable(path):
 
     This may raise IOError or SyntaxError.
     """
-    with open(path, b'rb') as src:
+    with open(path, 'rb') as src:
         root = ast.parse(src.read(), path)
     cmdtable = {}