4.0.0: no longer expands ~ properly

As can be seen in this CI run: https://github.com/boostorg/hash2/actions/runs/14209914156/job/39815091494, which passes -DCMAKE_INSTALL_PREFIX=~/.local, the tilde is no longer being expanded by CMake 4, which results in installing into

-- Installing: /home/runner/work/hash2/boost-root/__build__/~/.local/include

instead of /home/runner/.local as intended.

This is a regression compared to earlier CMake versions.

assigned to @brad.king

added triage:regression label

changed milestone to %4.0.1

changed title from CMake 4 no longer expands ~ properly to 4.0.0: no longer expands ~ properly

This bisects to commit 622596c6 from !9969 (merged).

mentioned in merge request !10580 (merged)

!10580 (merged) fixes this.

closed with commit 01f92efe