MNT Use Brotli compression for package artifacts

[rth]

Use Brotli compression on built packages before uploading them to the artifact storage, as suggested by @MartinKolarik

Should have no impact on users, but should reduce the download size (and therefore data transfer costs) between the artifact storage and the CDN.

(I tested earlier that this is working fine).

[MartinKolarik]

Note that this will NOT work in your current setup because CF doesn't support fetching brotli files from the origin.

[rth]

Thanks @MartinKolarik . What I checked previously was that is you upload them br compressed, CF will serve them fine with the associated header. However if the request is Accept-Encoding:gzip it will indeed fail to re-encode them to gzip. So I guess for now are limited to gzip compression at the origin which should be supported by CF.