Add Tests for PR#45

[codecov-ai]

This PR adds tests for #45

Commits:

• Add unit tests for get_constant_tensor function

This commit adds a new test file to validate the newly added get_constant_tensor function.
The tests cover various scenarios including direct constant values, values without producer nodes,
values with non-Constant producer nodes, and values produced by Constant nodes with different
attribute types (float, int, tensor).

[codecov]

❌ 6 Tests Failed:

Tests completed	Failed	Passed	Skipped
580	6	574	0

View the top 3 failed test(s) by shortest run time

src.onnx_ir._convenience.get_constant_tensor_test.GetConstantTensorTest::test_constant_float_value

Stack Traces | 0.002s run time

src\onnx_ir\_convenience\get_constant_tensor_test.py:54: in test_constant_float_value
    graph = _core.Graph(name="test_graph")
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
E   TypeError: Graph.__init__() missing 2 required positional arguments: 'inputs' and 'outputs'

src.onnx_ir._convenience.get_constant_tensor_test.GetConstantTensorTest::test_constant_tensor_value

Stack Traces | 0.002s run time

src\onnx_ir\_convenience\get_constant_tensor_test.py:98: in test_constant_tensor_value
    graph = _core.Graph(name="test_graph")
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
E   TypeError: Graph.__init__() missing 2 required positional arguments: 'inputs' and 'outputs'

src.onnx_ir._convenience.get_constant_tensor_test.GetConstantTensorTest::test_no_producer_node

Stack Traces | 0.002s run time

src\onnx_ir\_convenience\get_constant_tensor_test.py:28: in test_no_producer_node
    value = _core.Value(name="test_value", type=_core.TensorType(elem_type=_enums.DataType.FLOAT))
                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
E   TypeError: _TensorTypeBase.__init__() got an unexpected keyword argument 'elem_type'

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[github-advanced-security]

lintrunner found more than 20 potential problems in the proposed changes. Check the Files changed tab for more details.