Issue #27285: Document the deprecation of the pyvenv script.

As part of the update, the documentation was updated to normalize
around the term "virtual environment" instead of relying too heavily
on "venv" for the same meaning and leading to inconsistent usage of
either.

Thanks to Steve Piercy for the patch.
diff --git a/Misc/ACKS b/Misc/ACKS
index 9494406..25ddb78 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1150,6 +1150,7 @@
 Christopher J. Phoenix
 James Pickering
 Neale Pickett
+Steve Piercy
 Jim St. Pierre
 Dan Pierson
 Martijn Pieters