Ignore tags in universal resolution (#4174)
## Summary
If a package lacks a source distribution, and we can't find a compatible
wheel for the current platform, we need to just _assume_ that the
package will have a valid wheel on all platforms on which it's
requested; if not, we raise an error at install time.
It's possible that we can be smarter about this over time. For example,
if the package was requested _only_ for macOS, we could verify that
there's at least one macOS-compatible wheel. See the linked issue for
more details.
Closes https://github.com/astral-sh/uv/issues/4139.
