Smoke test LTC in release build

[henrytwo]

Re: https://github.com/llvm/torch-mlir/pull/1283#issuecomment-1227744684

https://github.com/llvm/torch-mlir/pull/1283 resolves an issue with the release build of Torch-MLIR where the shared libraries for LTC were not being properly discovered. This was not detected earlier, since CI tests are run in the same location where the source is built.

The library import error only arose when the wheels were installed in a different environment.

It would be beneficial to add a test to LTC to ensure that the wheels behave as expected.

[silvasean]

@powderluv is this still doing a "smoke test"? I looked into the script and it doesn't appear to be:

https://github.com/llvm/torch-mlir/blob/a1ace0657d1027a82b09a652a157a4c45e9d62d1/.github/workflows/buildRelease.yml#L25