Light-the-torch

- Add support for CUDA 11.7 and 11.8 by lassoan (108)
- Add support for `pip==22.3.1` (105)

This release is needed since `pip==22.3` breaks previous `light-the-torch` versions. Compatibility was fixed in 99.

Apart from that, this release brings a few other quality-of-life improvements:

- use PyPI as fallback if stable binaries are not on PyTorch indices (93)
- improve CLI help messages (94)
- add option to specify computation backend through environment variable (102)

* use PyPI as fallback if stable binaries are not on PyTorch indices (93)
* improve CLI help messages (94)
* Update to `pip==22.3` by (99)
* add option to specify computation backend through environment variable by (102)

If you want to install this version of `light-the-torch`, use `pip install --pre light-the-torch`

* Expand test matrix to also install different computation backends 80

* exclude torchrec from patched distributions 85
* add support for pip==22.2 89

As noted in 40, the supported `pip` versions before this release were quite outdated. A major blocker was the dependency resolver that `pip==21` introduced. It changed a lot of the internals that we relied on. Thus, we needed to completely overhaul the project.

And we did in 60 :tada: As a result, we now support every `pip` version starting from `22` with a few exceptions. Of course, given that we need to rely on `pip` internals without any BC guarantees, there will be some breakages in future version. But we are confident, that the changes that needed to happen in `light-the-torch` should be small.

In the process of rewriting, we also added support for other PyTorch distributions to be installed through `light-the-torch`. Before it could only handle

- `torch`
- `torchvision`
- `torchtext`
- `torchaudio`

but now in addition we support:

- `torch`
- `torch_model_archiver`
- `torch_tb_profiler`
- `torcharrow`
- `torchcsprng`
- `torchdata`
- `torchdistx`
- `torchserve`

Unfortunately, overhauling the project also brings some BC breaking changes. Namely, `ltt extract` and `ltt find` and their API counterparts `light_the_torch.extract_dists` and `light_the_torch.find_links` were removed. This processing in stages, i.e. extracting the PyTorch distributions from the installation command, finding the correct link for them and only then installing them in a subsequent command is no longer possible with the new `pip` dependency resolver.

Shout out to our contributors: pmeier tonyfast jamesobutler