Given recent changes in corp, I originally thought we could remove all of the
syso files, but then I realized that we still need them so that binaries built
purely from OSS (without going through corp) will still receive a manifest.
We can remove the arm32 one though, since we don't support 32-bit ARM on Windows.
Updates https://github.com/tailscale/corp/issues/9576
Signed-off-by: Aaron Klotz <aaron@tailscale.com>