feat: Enable Windows Support for `rules_uv`

Currently, the rule set fails on Windows.

I was able to partially workaround this by wrapping the `pip_compile` into `sh_binary`. This resolves the issue of executing the shell script; however, another issue is the path, as `../` is not where rules_multitol is located. It's `../../external/rules_multitool`.

That certainly has to do with runfiles / rlocation.

I will add more details as I investigate this further.

Gazelle currently uses shell scripts as well and supports Windows.

Reference for inspiration on possible fixes and enhancements on the implementation: https://github.com/bazel-contrib/bazel-gazelle/blob/0990b28954080252c89369d7a27176aee7381ab5/def.bzl

Step 1 is most likely to wrap all shell executables into a `sh_binary` rule.

While creating a venv, the same runfiles issue occurs, but it also currently expects to source `$target/bin/activate`, whereas on Windows, it must be `$target/Scripts/activate`.

Start with the rules_uv pip_compile and virtual-environment creation paths, then compare their shell executable and runfiles handling with the referenced Bazel Gazelle def.bzl implementation. Verify Windows execution, rules_multitool resolution through runfiles, and the Windows venv activation path under target/Scripts/activate.

Written by the indexing model from the issue text.