Add support for Windows legacy scripts via uv tool run (#12079)
## Summary
Follow up to https://github.com/astral-sh/uv/pull/11888 with added
support for uv tool run.
Changes
* Added functionality for running windows scripts in previous PR was
moved from run.rs to uv_shell::runnable.
* EXE was added as a supported type, this simplified integration across
both uv run and uvx while retaining a backwards compatible behavior and
properly prioritizing .exe over others. Name was adjusted to runnable as
a result to better represent intent.
## Test Plan
New tests added.
## Documentation
Added new documentation.
