resourceutil: start using importlib.resources.files() when possible

This avoids DeprecationWarnings related to our use of resources.open_binary()
on Python 3.11.

mercurial/utils/resourceutil.py

@@ -59,6 +59,9 b' try:'
     from importlib import resources  # pytype: disable=import-error
 
     # Force loading of the resources module
+    if pycompat.safehasattr(resources, 'files'):
+        resources.files  # pytype: disable=module-attr
+    else:
     resources.open_binary  # pytype: disable=module-attr
 
     # py2exe raises an AssertionError if uses importlib.resources
@@ -92,6 +95,15 b' else:'
     from .. import encoding
 
     def open_resource(package, name):
+        if pycompat.safehasattr(resources, 'files'):
+            return (
+                resources.files(  # pytype: disable=module-attr
+                    pycompat.sysstr(package)
+                )
+                .joinpath(pycompat.sysstr(name))
+                .open('rb')
+            )
+        else:
         return resources.open_binary(  # pytype: disable=module-attr
             pycompat.sysstr(package), pycompat.sysstr(name)
         )