Add repodata.json.zst

[jonashaag]

Conda recently added a zstd compression version of repodata.json: https://github.com/conda/infra/issues/648

Would be great to have it here as well!

[simonbohnen]

I might look into this! Compression seems to be tested here for quetz: https://github.com/mamba-org/quetz/blob/6cdf96e69ecae68fd9e7fe9b0efebe5ac5957f06/quetz/tests/test_indexing.py#L16

And creation of the repodata files happens here: https://github.com/mamba-org/quetz/blob/6cdf96e69ecae68fd9e7fe9b0efebe5ac5957f06/quetz/tasks/indexing.py#L211

And this uses the following function to actually write the file, including encrypted versions. Adding zst should probably happen here? https://github.com/mamba-org/quetz/blob/6cdf96e69ecae68fd9e7fe9b0efebe5ac5957f06/quetz/utils.py#L61

[wolfv]

yep, that sounds correct! :)

[iklues17]

I am using version 0.9.2. In proxy mode, the repodata.json.zst file is not updated after initial creation.

[beenje]

I am using version 0.9.2. In proxy mode, the repodata.json.zst file is not updated after initial creation.

Just found the same issue. This is a problem as mamba is using that file by default.