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 many 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. In an indication of the possible scale of the RIF, CISA had planned to keep just 889 employees on duty during a shutdown while furloughing 65%...