Fix - set random seed in optuna example (skrub-data#1814)

Author: rcap107

examples/data_ops/1131_optuna_choices.py

@@ -81,7 +81,9 @@
 # the User Guide for an example.
 
 # %%
-search = pred.skb.make_randomized_search(backend="optuna", cv=cv, n_iter=10)
+search = pred.skb.make_randomized_search(
+    backend="optuna", cv=cv, n_iter=10, random_state=10
+)
 search.fit(env)
 search.results_