Add pytorch_jit sample Colab notebook using SHARK-Turbine.  (#15146)

Progress on https://github.com/openxla/iree/issues/15117

This notebook shows how to use
[SHARK-Turbine](https://github.com/nod-ai/SHARK-Turbine) for eager
execution within a PyTorch session using IREE and
[torch-mlir](https://github.com/llvm/torch-mlir) under the covers. I'm
starting simple to get the concepts across, with minimal API usage and a
tiny `nn.Module` sourced from
https://pytorch.org/docs/stable/notes/modules.html. My expectation is
that this notebook will evolve alongside other notebooks (e.g.
`pytorch_aot.ipynb`), documentation
(https://github.com/openxla/iree/issues/15114), and the SHARK-Turbine
project itself.

Preview URL for review:
https://colab.research.google.com/github/openxla/iree/blob/scotttodd-pytorch-samples-1/samples/colab/pytorch_jit.ipynb

skip-ci: no-op
diff --git a/samples/colab/test_notebooks.py b/samples/colab/test_notebooks.py
index 984002c..17ca31e 100755
--- a/samples/colab/test_notebooks.py
+++ b/samples/colab/test_notebooks.py
@@ -15,6 +15,8 @@
     # tflite_runtime requires some deps ("version `GLIBC_2.29' not found") that
     # samples.Dockerfile does not currently include.
     "tflite_text_classification.ipynb",
+    # Requires Python 3.10+ in our Docker image.
+    "pytorch_jit.ipynb",
 ]
 
 NOTEBOOKS_EXPECTED_TO_FAIL = [