Install nightly CMake

[madebr]

It would be interesting to be able to install the nightly CMake version(s).
We'd like to add visionOS to our testing matrix, but this is currently only available in the nightlies.

[jwlawson]

Hmm yeah I can see how that might be helpful. Unfortunately this action is currently fairly tightly coupled to pulling the releases from github rather than other sources so I guess it will be fairly involved to add support.