Fallback install tests are not covered in CI

[yingsu00]

Problem description

In Upgrade FBOS dependencies to 2024.09.16.00, there was a URL error (missing ref/tags/) in fast_float.cmake (see #11056), but the CI didn't report any error (presuming all tests passed before merging).
Moreover, the CI also didn't catch the error running setup-macos.sh when installing fast_float.

Shall we add proper coverage testing the system setups?

System information

N/A

CMake log

No response

[yingsu00]

cc @assignUser @kgpai @majetideepak @czentgr

[majetideepak]

@yingsu00 We should throw an error in such instances. I wonder how CI passed even though the dependency did not install.
The image build CI jobs should have failed.

[majetideepak]

@czentgr is adding a bundled-only and scripts-only CI job for macos here #10670.
That should improve the coverage.

[assignUser]

As seen in #11056 the url without ref/tag also works but seems to have had some downtime when running this locally.
The reason why the docker ci didn't fail is because the install worked there.

We use set -e in the install scripts so any error while immediately kill the script.