gitignore: ignore *.VC.db files

PR-URL: #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>

.gitignore

@@ -57,6 +57,7 @@ _UpgradeReport_Files/
 ipch/
 *.sdf
 *.opensdf
+*.VC.db
 *.VC.opendb
 .vs/
 .vscode/