Enable torch.compile support for torch 2.0.0 pre release

[morgandu]

We are currently locked on an alpha version of torch 2.0.0. TorchServe (HEAD) was working for us before the PT2 refactor when the base_handler was deciding PT2, as below:

    try:
        import torch._dynamo

        pt2_enabled = True

Creating a minor PR for enable torch2.0.0 alpha pre release to use torch.compile.

[codecov]

Codecov Report

Merging #2256 (6a14ef3) into master (627d4b7) will not change coverage.
The diff coverage is 100.00%.

❗ Current head 6a14ef3 differs from pull request most recent head c5a34b9. Consider uploading reports for the commit c5a34b9 to get more accurate results

@@           Coverage Diff           @@
##           master    #2256   +/-   ##
=======================================
  Coverage   70.40%   70.40%           
=======================================
  Files          75       75           
  Lines        3392     3392           
  Branches       57       57           
=======================================
  Hits         2388     2388           
  Misses       1001     1001           
  Partials        3        3           

Impacted Files	Coverage Δ
ts/torch_handler/base_handler.py	55.50% <100.00%> (ø)

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[agunapal]

@msaroufim I wonder if the fix should be to change the logic to just check for >= 2 in 2.x.x

[agunapal]

@morgandu Could you please share whats the context of this alpha release. Also, the proposed fix would mean torch.compile wouldn't work on 2.0.0?

[msaroufim]

@agunapal for context this PR is needed for the new TPU support, I believe this PR is correct and will return True in the case of torch__version__ = 2.0.0 since that's considered greater than an alpha release

[morgandu]

@morgandu Could you please share whats the context of this alpha release. Also, the proposed fix would mean torch.compile wouldn't work on 2.0.0?

@agunapal we are currently fixed on using a particular version of torch 2.0.0, which is an alpha pre release version. According to the packaging.version comparison. '2.0.0a0' < '2.0.0'. However, I believe dynamo is enabled in '2.0.0a0'.

So this change should enable the torch.compile support for users on any pre release of 2.0.0, but not lower, and it will not affect users on 2.0.0 official release / post release and other future versions above 2.0.0.

[morgandu]

All green but I don't have write access so can't merge myself. Please help merge this PR. Thanks!