release: embed signed vscgo binaries in the extension

[hyangah]

Follow up of #3182

Then, revert the change https://go.dev/cl/565679 to enable vscgo on windows.

[gopherbot]

Change https://go.dev/cl/571575 mentions this issue: internal/relui/sign: add binary artifact signing modes

[gopherbot]

Change https://go.dev/cl/587735 mentions this issue: internal/task: change buildVSCGO to produce zip files

[gopherbot]

Change https://go.dev/cl/595376 mentions this issue: extension/tools/release: add build-vscgo subcommand