Add Cryptodome to maintainer requirements

See e.g. https://github.com/ARMmbed/mbedtls/pull/5218

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/scripts/maintainer.requirements.txt b/scripts/maintainer.requirements.txt
index 670617b..b149921 100644
--- a/scripts/maintainer.requirements.txt
+++ b/scripts/maintainer.requirements.txt
@@ -4,3 +4,7 @@
 
 # For source code analyses
 clang
+
+# For building some test vectors
+pycryptodomex
+pycryptodome-test-vectors