[CI] invalid_param reliability suite and weekly http_invalid jobs (#3652)

Signed-off-by: wangyu <410167048@qq.com>

tests/dfx/reliability/invalid_param_test/conftest.py

@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+"""Shared env for ``http_invalid`` (real :func:`omni_server`)."""
+
+from __future__ import annotations
+
+import io
+import os
+
+import pytest
+from PIL import Image
+
+# Match ``tests/e2e/online_serving/*`` module-level env for subprocess serve.
+os.environ.setdefault("VLLM_WORKER_MULTIPROC_METHOD", "spawn")
+os.environ.setdefault("VLLM_TEST_CLEAN_GPU_MEMORY", "0")
+
+
+@pytest.fixture
+def tiny_png_bytes() -> bytes:
+    img = Image.new("RGB", (32, 32), color="gray")
+    buf = io.BytesIO()
+    img.save(buf, format="PNG")
+    return buf.getvalue()