[Py OV] Add deprecation warning for runtime module (#27694)

### Details:
Add deprecation warning for `openvino.runtime` that will be shown
**ONCE** when sb will access runtime functionality for the first time.
Examples:
![Screenshot 2025-01-10
114701](https://github.com/user-attachments/assets/4229ede3-3b86-418a-8dbf-f230ff91983b)

![warn_updated](https://github.com/user-attachments/assets/4b4a7c56-c5ca-4b7b-8b34-f89f3a4bc627)

`openvino.runtime` funtionality was added to openvino namespace in these
PRs:
- #27785
- #27902
- #28007
- #28062
- #28085

Internal calls in `openvino` module also triggered warning, so they were
updated:
 - #28166 
 - #28356

### Tickets:
 - [CVS-129451](https://jira.devtools.intel.com/browse/CVS-129451)

---------

Signed-off-by: Alicja Miloszewska <alicja.miloszewska@intel.com>
Co-authored-by: Anastasia Kuporosova <anastasia.kuporosova@intel.com>

src/bindings/python/src/openvino/__init__.py

@@ -60,7 +60,8 @@
 from openvino._ov_api import Op
 
 # Import all public modules
-from openvino import runtime as runtime
+from openvino.package_utils import lazy_import
+runtime = lazy_import("openvino.runtime")
 from openvino import frontend as frontend
 from openvino import helpers as helpers
 from openvino import experimental as experimental

src/bindings/python/src/openvino/package_utils.py

@@ -7,6 +7,8 @@
 from functools import wraps
 from typing import Callable, Any
 from pathlib import Path
+import importlib.util
+from types import ModuleType
 
 
 def _add_openvino_libs_to_search_path() -> None:
@@ -113,3 +115,19 @@ def __get__(self, obj: Any, cls: Any = None) -> Any:
         _patch(func, deprecated(name, version, message, stacklevel))
         return func
     return decorator
+
+
+def lazy_import(module_name: str) -> ModuleType:
+    spec = importlib.util.find_spec(module_name)
+    if spec is None or spec.loader is None:
+        raise ImportError(f"Module {module_name} not found")
+
+    loader = importlib.util.LazyLoader(spec.loader)
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[module_name] = module
+
+    try:
+        loader.exec_module(module)
+    except Exception as e:
+        raise ImportError(f"Failed to load module {module_name}") from e
+    return module

src/bindings/python/src/openvino/runtime/__init__.py

@@ -5,6 +5,16 @@
 """openvino module namespace, exposing factory functions for all ops and other classes."""
 # noqa: F401
 
+import warnings
+warnings.simplefilter("always", DeprecationWarning)
+warnings.warn(
+    "The `openvino.runtime` module is deprecated and will be removed in the 2026.0 release. "
+    "Please replace `openvino.runtime` with `openvino`.",
+    DeprecationWarning,
+    stacklevel=2
+)
+
+
 from openvino._pyopenvino import get_version
 
 __version__ = get_version()

src/bindings/python/tests/test_runtime/test_deprecated_runtime.py

@@ -6,9 +6,12 @@
 import numpy as np
 from pathlib import Path
 from contextlib import nullcontext as does_not_raise
+import warnings
 
+with pytest.warns(DeprecationWarning, match="The `openvino.runtime` module is deprecated and will be removed in the 2026.0 release."):
+    import openvino.runtime as ov
 
-import openvino.runtime as ov
+import openvino.runtime.opset13 as ops
 from openvino.runtime import (
     Model,
     Core,
@@ -19,8 +22,6 @@
     serialize,
     Type,
 )
-
-import openvino.runtime.opset13 as ops
 import openvino.runtime.opset8 as ops8
 from openvino.runtime.op import Constant, Parameter
 from openvino.runtime import Extension
@@ -42,6 +43,17 @@
 )
 
 
+def test_no_warning():
+    with warnings.catch_warnings(record=True) as w:
+        import openvino
+
+        data = np.array([1, 2, 3])
+        axis_vector = openvino.AxisVector(data)
+        assert np.equal(axis_vector, data).all()
+
+        assert len(w) == 0  # No warning
+
+
 # request - https://docs.pytest.org/en/7.1.x/reference/reference.html#request
 def test_read_model_from_ir(request, tmp_path):
     core = Core()

tools/benchmark_tool/openvino/__init__.py

@@ -60,7 +60,8 @@
 from openvino._ov_api import Op
 
 # Import all public modules
-from openvino import runtime as runtime
+from openvino.package_utils import lazy_import
+runtime = lazy_import("openvino.runtime")
 from openvino import frontend as frontend
 from openvino import helpers as helpers
 from openvino import experimental as experimental

tools/ovc/openvino/__init__.py

@@ -60,7 +60,8 @@
 from openvino._ov_api import Op
 
 # Import all public modules
-from openvino import runtime as runtime
+from openvino.package_utils import lazy_import
+runtime = lazy_import("openvino.runtime")
 from openvino import frontend as frontend
 from openvino import helpers as helpers
 from openvino import experimental as experimental