Attempt to speed up Windows builds using a dev drive

[obi1kenobi]

Dev Drives on Windows are designed to speed up common dev operations by double digit percentages.

Our Windows builds are quite slow: a cache-miss build takes 12min+, and even a successful mostly-cached build takes about a minute and a half.

Other Rust tools have figured out how to set up and use a dev drive on Windows:
https://github.com/astral-sh/uv/blob/db33497974f0baf74f3914d31e879b3cd2e4250f/.github/workflows/ci.yml#L229-L237

We should:

• try to apply what they've learned to our own builds
• then, measure the perf impact and use that to determine whether to apply the change or not

Related to #665.