Feature request: Sharded archive tests artifcats

[gen-xu]

Motivation

Currently, the nextest archive feature stores all test binaries in a single .tar.zst file. This approach can be inefficient—especially when the downstream consumer only runs tests using the --partition flag. In such cases, many of the archived binaries are unnecessary, yet they still incur time and resource costs during download and decompression.

Proposal

Supporting --partition option with the archive command, allowing the archive to include only the relevant subset of test binaries.

Alternatives

No response

Additional context

No response

[sunshowers]

Related: #2648