[Q] what's git-sdk-64-minimal.tar.gz from wingit?

[Junio C Hamano <gitster@xxxxxxxxx>]

For the past few days CI/PR windows-build and friends on any branch
seem to be failing quite early in "downlaod git-sdk-64-minimal" step.

    a=git-sdk-64-minimal && 
    mkdir -p $a && 
    curl -#
    https://wingit.blob.core.windows.net/ci-artifacts/$a.tar.xz |
    tar -C $a -xJf -

It seems like we are getting 404 equivalent?

<?xml version="1.0" encoding="utf-8"?><Error><Code>BlobNotFound</Code><Message>The specified blob does not exist.
RequestId:51b9fae0-d01e-0121-259c-281a07000000
Time:2020-05-12T20:32:10.7112978Z</Message></Error>