Update torch version

[adam-smnk]

Bumps torch to the newest stable release.

[adam-smnk]

Generally works although our CI has limited coverage.
@rolfmorel Do you know if there's any deeper dependency on torch version and torch-mlir? Or is it safe to freely bump?

[rolfmorel]

torch-mlir's development version (which we use pinned nightlies of) seems to be keeping up with relatively recent development versions of torch: https://github.com/llvm/torch-mlir/blob/main/pytorch-requirements.txt & https://github.com/llvm/torch-mlir/commits/main/pytorch-requirements.txt I don't know how much effort goes into compatibility with older versions (though presumably some).

At the moment torch-mlir's main is tracking llvm-project quite closely as well: https://github.com/llvm/torch-mlir/commits/main/externals. Which is good for us as I expect the biggest pain would be if torch-mlir built with a llvm-project commit far away in time from lighthouse's mlir-python-bindings's llvm-project commit, as MLIR's textual format (for particular ops) might have experienced some drift. The issues associated with that would indeed only start to turn up as we reach (more) thorough testing.