DUBAI, UNITED ARAB EMIRATES — An oil tanker that burned for weeks in the Red Sea after being attacked by Yemen’s Houthi rebels and threatening a massive oil spill has been salvaged, a security firm said Friday. The Sounion had been a disaster-in-waiting in the waterway, with 1 million barrels of crude oil aboard that had been struck and later sabotaged with explosives by the Iranian-backed Houthis as part of their campaign over the Israel-Hamas war in the Gaza Strip. It took months for salvagers to tow the vessel away, extinguish the fires and offload the remaining crude oil. “Over