gitignore: ignore *.VC.db files

PR-URL: https://github.com/nodejs/node/pull/17898


Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Bartosz Sosnowski <bartosz@janeasystems.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>