ext: Update ply to version 3.11.

We had been using version 3.2 from 2009, which does not have support for
t_eof().

Change-Id: Id5610a272fe2cecd586991f4c59f3ec77184164e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/56342
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

ext/ply/setup.cfg

@@ -0,0 +1,10 @@
+[bdist_wheel]
+universal = 1
+
+[metadata]
+description-file = README.md
+
+[egg_info]
+tag_build = 
+tag_date = 0
+