Build broken on many platforms - error about libtiff

[olsen232]

Looks something like
error: building tiff:x64-linux failed with: BUILD_FAILED

Happens for many platforms, but not always, but reliably enough that our build hasn't been green since it started happening.
For instance, in this run, it happened 3 times - in the linux-dev, macos for x64, and windows builds:
https://github.com/koordinates/kart/actions/runs/8643796713

On other runs it may happen for a different set of platforms.

This is filed upstream as microsoft/vcpkg#38116
And is caused by microsoft/vcpkg#37968
which basically says that cmake 3.29.1 has broken something to do with how package paths are resolved and is now installed on GH actions. It's rolled back on 3.29.2.
Some mild finger pointing happening on the bug there in terms of which subsystem is working according to spec and which is defective, so, not sure what will happen next - hopefully whatever action they take, it won't break in the same way again.

Will try to upgrade our cmake to 3.29.2