Latvian Prime Minister Evika Silina on Thursday said she was resigning in response to her coalition government breaking up.  "I am resigning, but I am not giving up," Silina said in a televised statement.  Silina, of the center-right New Unity party, was left without a ruling majority in the parliament as of Wednesday, when the left-wing Progressive party said it was withdrawing its support.  This followed the removal of former Defense Minister Andris Spruds, a member of the Progressives, over the handling of incidents of stray Ukrainian drones flying into Latvia from Russia. Two major Russian oil facilities in the Baltic are located near the borders to Estonia and Latvia.…