[samples] Update PyTorch JIT notebook for Python 3.12 (iree-org#22209)

The PyTorch JIT sample notebook fails on Python 3.12 with `RuntimeError:
Dynamo is not supported on Python 3.12+` because it installs PyTorch
2.3.0, which lacks Python 3.12 support. Additionally, the expected MLIR
output shown in the notebook does not appear when running with newer
versions.

Update the PyTorch installation to use the latest stable version from
the CPU index, which supports Python 3.12. Add the
`TURBINE_LOG_LEVEL=debug` environment variable to enable verbose
compilation output, including intermediate MLIR representations. Update
the sample execution outputs to reflect the new versions.

Signed-off-by: HeatCrab <[email protected]>

Author: HeatCrab