WASHINGTON — The Cybersecurity and Infrastructure Security Agency (CISA) is among the offices being permanently downsized as a result of the ongoing partial government shutdown, The Post has learned. The RIFs ( reductions in force ), which started Friday, will fire some of CISA’s 2,540 employees as well as thousands more within the federal bureaucracy — after President Trump repeatedly threatened to target offices cherished by Democrats if the party’s senators refused to reopen the government.