uv

64e91a7e - Fix handling of `python-preference = system` when managed interpreters are on the PATH (#15059)

Fix handling of `python-preference = system` when managed interpreters are on the PATH (#15059) This is the first part of fixing a 0.8.0 regression from https://github.com/astral-sh/uv/pull/7934 There, we added handling for skipping managed interpreters on the PATH when `only-system` is used, but did not update the logic to prefer system interpreters over managed ones when `system` is used. Here, we fix that by skipping managed interpreters when `system` is used unless _only_ managed interpreters are available. While this logic is applied during in a general discovery method, it's only relevant for the PATH (and the Windows registry) because we already change the _order_ that we inspect installations in when `system` is used, so the managed installation directory is inspected last. This behavior did not regress in 0.8, it's always been this way, however, I need this change in order to fix a different bug.