Add per-test case timeouts to flow tests

Adds a per testcase timeout for tests in backends/test/suite. The
timeout is set to 1200s for models and 120s for ops.

Signed-off-by: Oscar Andersson <oscar.andersson@arm.com>
Change-Id: Iebf0d520953a10b2e7934b7f3540a2e6a2806e38

Author: oscarandersson8218

backends/test/suite/conftest.py

@@ -1,3 +1,8 @@
+# Copyright 2026 Arm Limited and/or its affiliates.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
 import os
 from typing import Any
 
@@ -9,19 +14,29 @@
 from executorch.backends.test.suite.runner import run_test
 
 
+FLOW_TEST_CASE_TIMEOUTS = {
+    "backends/test/suite/models/": 1200,
+    "backends/test/suite/operators/": 120,
+}
+
+
 def pytest_collection_modifyitems(config, items):
     for item in items:
         callspec = getattr(item, "callspec", None)
-        if callspec is None:
-            continue
-        flow = callspec.params.get("test_runner")
-        if not isinstance(flow, TestFlow):
-            continue
-        test_name = item.originalname or item.name
-        if flow.should_skip_test(test_name):
-            item.add_marker(
-                pytest.mark.skip(reason=f"Skipped by {flow.name} skip_patterns")
-            )
+        if callspec is not None:
+            flow = callspec.params.get("test_runner")
+            if isinstance(flow, TestFlow):
+                test_name = item.originalname or item.name
+                if flow.should_skip_test(test_name):
+                    item.add_marker(
+                        pytest.mark.skip(reason=f"Skipped by {flow.name} skip_patterns")
+                    )
+
+        item_path = str(getattr(item, "path", ""))
+        for suite_prefix, timeout_s in FLOW_TEST_CASE_TIMEOUTS.items():
+            if suite_prefix in item_path:
+                item.add_marker(pytest.mark.timeout(timeout_s))
+                break
 
 
 def pytest_configure(config):