Allow caching without compression

[SanjayVas]

Allowing one to choose not to compress the tar archive when caching. This allows for the useful tradeoff between time and cache entry size. Note that cache size is already bounded by the total per-repo limit.

Compression frequently takes up the majority of the time spent in a cache save step, so this could offer a significant time savings at the cost of size.

This is a more specific version of #544.

[planetmarshall]

This would also be useful for users of the conan package manager which has its own method of creating cache archives and the purpose of the cache action would purely be to upload and download the prepared archives.

[anton-danielsson]

This would also be useful for users of the conan package manager which has its own method of creating cache archives and the purpose of the cache action would purely be to upload and download the prepared archives.

Exactly what brought me here 🙂
Would be very nice to have this option.

[andrewchambers]

Compressing/decompressing already compressed data is a huge waste of resources, avoiding that makes a lot of sense.

[planetmarshall]

Would you accept a PR for this feature? Would probably also implement #544