hxtorch will soon depend on jax

We have been extending hxtorch.snn towards supporting event-based processing; we use jax for this purpose.

This MR adds this dependency of hxtorch on py-jax and py-tree-math.

packages/bazel/add-include-limits-0.25.patch

+diff -pur third_party/ijar/mapped_file_unix.cc third_party/ijar/mapped_file_unix.cc
+--- third_party/ijar/mapped_file_unix.cc	2021-10-05 15:24:37.243946507 +0200
++++ third_party/ijar/mapped_file_unix.cc	2021-10-05 15:24:28.707823401 +0200
+@@ -19,6 +19,7 @@
+ #include <sys/mman.h>
+ 
+ #include <algorithm>
++#include <limits>
+ 
+ #include "third_party/ijar/mapped_file.h"
+