bpo-29435: Allow is_tarfile to take a filelike obj (GH-18090)

`is_tarfile()` now supports `name` being a file or file-like object.
diff --git a/Misc/ACKS b/Misc/ACKS
index 3e45d5d..7e4b81b 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1856,6 +1856,7 @@
 Dan Wolfe
 Richard Wolff
 Adam Woodbeck
+William Woodruff
 Steven Work
 Gordon Worley
 Darren Worrall