Update @python_gtk for Debian 11

This following now gets to a point where it's looking for a display I
think.

    $ bazel run -c opt frc971/control_loops/python:spline_graph

Signed-off-by: Philipp Schrader <philipp.schrader@gmail.com>
Change-Id: I8afe41608cd0d2ca437e73e18af5df7471c96652
diff --git a/debian/python_gtk.BUILD b/debian/python_gtk.BUILD
index a6a4fe4..7fdb3b9 100644
--- a/debian/python_gtk.BUILD
+++ b/debian/python_gtk.BUILD
@@ -70,7 +70,7 @@
 _src_copied = ["/".join(f.split("/")[4:]) for f in _src_files]
 
 _builtin_so_files = glob([
-    "usr/lib/python3/dist-packages/**/*.cpython-37m-x86_64-linux-gnu.so",
+    "usr/lib/python3/dist-packages/**/*.cpython-39-x86_64-linux-gnu.so",
 ])
 
 _system_so_files = glob(
@@ -79,7 +79,7 @@
         "usr/lib/**/*.so*",
     ],
     exclude = [
-        "usr/lib/**/*.cpython-37m-x86_64-linux-gnu.so",
+        "usr/lib/**/*.cpython-39-x86_64-linux-gnu.so",
         "usr/lib/gcc/x86_64-linux-gnu/6/libgcc_s.so.1",
         "usr/lib/gcc/x86_64-linux-gnu/6/libgcc_s.so",
     ],