[systemtest] Disable OTBN test with model

This test won't work until the Python model is discoverable in
out-of-source-tree runs.

Signed-off-by: Philipp Wagner <phw@lowrisc.org>

test/systemtest/config.py

diff --git a/test/systemtest/config.py b/test/systemtest/config.py
index 909d3cd..9983cba 100644
--- a/test/systemtest/config.py
+++ b/test/systemtest/config.py
@@ -29,12 +29,13 @@
         "binary_name": "dif_otbn_sanitytest",
         "verilator_extra_args": ['+OTBN_USE_MODEL=0'],
     },
-    {
-        "name": "dif_otbn_sanitytest_model",
-        "binary_name": "dif_otbn_sanitytest",
-        "verilator_extra_args": ['+OTBN_USE_MODEL=1'],
-        "targets": ["sim_verilator"],
-    },
+# Using the model in CI isn't possible until #4097 is resolved.
+#    {
+#        "name": "dif_otbn_sanitytest_model",
+#        "binary_name": "dif_otbn_sanitytest",
+#        "verilator_extra_args": ['+OTBN_USE_MODEL=1'],
+#        "targets": ["sim_verilator"],
+#    },
     {
         "name": "dif_plic_sanitytest",
     },