dilithium_py reproducible output requires pycryptodome

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

util/requirements.txt

diff --git a/util/requirements.txt b/util/requirements.txt
index 113cb71..feb351e 100644
--- a/util/requirements.txt
+++ b/util/requirements.txt
@@ -1,4 +1,5 @@
 # Python module requirements for maintainer utilities
 
 # For generate_mldsa_tests.py
+pycryptodome
 dilithium-py >= 1.3.0; python_version >= "3.9"