src/vs/platform/backup/electron-main/backupMainService.ts/BackupMainService/unregisterFolderBackupSync
class BackupMainService:	unregisterFolderBackupSync(folderUri: URI): void {
		const index = this.folders.findIndex(folder => this.backupUriComparer.isEqual(folderUri, folder.folderUri));
		if (index !== -1) {
			this.folders.splice(index, 1);
			this.saveSync();
		}
	}