Use older NumPy while waiting for yourdfpy fix

Issue: clemense/yourdfpy#45

PR: clemense/yourdfpy#46

Author: stephane-caron

tox.ini

@@ -14,6 +14,7 @@ deps =
     coverage
     idyntree >= 8.0.0
     mujoco >=2.2.1
+    numpy <1.24.0
     pin >=2.6.10
     pybullet >=3.2.5
     robomeshcat >= 1.0.4