Provide daily Zig `master`-based toolset packages

[alexrp]

Download URLs can be determined from: https://ziglang.org/download/index.json

This will allow faster testing of Zig fixes as we no longer have to wait for a release. The package version can just be taken verbatim from the URL above. Note that not all platforms are built daily, so only a subset would be supported.

[alexrp]

Question: How do we process JSON in MSBuild?

[alexrp]

Question: How do we process JSON in MSBuild?

https://github.com/devlooped/json

[alexrp]

The only missing piece here is figuring out a central point in the build system where we can fetch index.json once, and set up the package version, download URLs, etc.

[alexrp]

The only missing piece here is figuring out a central point in the build system where we can fetch index.json once, and set up the package version, download URLs, etc.

It could just be a separate project that all the packaging projects are dependent on. The question then is: What incantation or condition should prompt that project to fetch a new index.json? Should it require manual intervention of some kind, a date change, or something else?

[alexrp]

The question then is: What incantation or condition should prompt that project to fetch a new index.json? Should it require manual intervention of some kind, a date change, or something else?

It should probably just always fetch it. This seems like the sensible behavior one would expect for builds based on Zig master.