Reject already-installed wheels that don't match the target platform (#15484)
## Summary
We've received several requests to validate that installed wheels match
the current Python platform. This isn't _super_ common, since it
requires that your platform changes in some meaningful way (e.g., you
switch from x86 to ARM), though in practice, it sounds like it _can_
happen in HPC environments. This seems like a good thing to do
regardless, so we now validate that the tags (as recoded in `WHEEL`) are
consistent with the current platform during installs.
Closes https://github.com/astral-sh/uv/issues/15035.