cherry pick 4028: fix resource partitioner issue from release branch to main

tests/py/dynamo/partitioning/conftest.py

@@ -0,0 +1,53 @@
+import copy
+
+import pytest
+from torch_tensorrt.dynamo.conversion._ConverterRegistry import (
+    DYNAMO_ATEN_CONVERTERS,
+    DYNAMO_CONVERTERS,
+)
+from torch_tensorrt.dynamo.partitioning._atomic_subgraphs import trace_atomic_graph
+
+
+@pytest.fixture(autouse=True)
+def reset_torch_tensorrt_state():
+    """
+    Ensure test isolation by restoring converter registry state and clearing caches.
+    This prevents earlier tests from mutating global state (e.g., disallowed targets)
+    which can cause different partitioning outcomes when running multiple tests.
+    """
+    # Snapshot current global state
+    original_registry = {k: list(v) for k, v in DYNAMO_ATEN_CONVERTERS.items()}
+    original_disallowed = set(getattr(DYNAMO_CONVERTERS, "disallowed_targets", set()))
+    original_settings = getattr(DYNAMO_CONVERTERS, "compilation_settings", None)
+
+    # Clear caches before running each test
+    try:
+        trace_atomic_graph.cache_clear()
+    except Exception:
+        pass
+
+    try:
+        yield
+    finally:
+        # Restore converter registry
+        DYNAMO_ATEN_CONVERTERS.clear()
+        DYNAMO_ATEN_CONVERTERS.update(
+            {k: list(v) for k, v in original_registry.items()}
+        )
+
+        # Restore disallowed targets and compilation settings
+        try:
+            DYNAMO_CONVERTERS.set_disallowed_targets(original_disallowed)
+        except Exception:
+            pass
+        if original_settings is not None:
+            try:
+                DYNAMO_CONVERTERS.set_compilation_settings(original_settings)
+            except Exception:
+                pass
+
+        # Clear caches again to avoid stale state carrying forward
+        try:
+            trace_atomic_graph.cache_clear()
+        except Exception:
+            pass