[otbn] Re-enable smoke test in CI (again)

Re-re-enable it: we should now have a working out-of-tree ISS plus
support for address errors.

Signed-off-by: Rupert Swarbrick <rswarbrick@lowrisc.org>
diff --git a/test/systemtest/config.py b/test/systemtest/config.py
index a3de7ac..0677548 100644
--- a/test/systemtest/config.py
+++ b/test/systemtest/config.py
@@ -29,13 +29,12 @@
         "binary_name": "dif_otbn_smoketest",
         "verilator_extra_args": ['+OTBN_USE_MODEL=0'],
     },
-# Using the model in CI isn't possible until #4097 is resolved.
-#    {
-#        "name": "dif_otbn_smoketest_model",
-#        "binary_name": "dif_otbn_smoketest",
-#        "verilator_extra_args": ['+OTBN_USE_MODEL=1'],
-#        "targets": ["sim_verilator"],
-#    },
+    {
+        "name": "dif_otbn_smoketest_model",
+        "binary_name": "dif_otbn_smoketest",
+        "verilator_extra_args": ['+OTBN_USE_MODEL=1'],
+        "targets": ["sim_verilator"],
+    },
     {
         "name": "dif_otp_ctrl_smoketest",
     },