Photo by Rick Rycroft of the Associated Press.FARMINGTON — The Regional School Unit 9 board of directors used much of Thursday’s meeting to discuss the district’s cellphone ban, a shortage of music teachers and the possibility of new behavioral support for students. The meeting followed the district’s June 9 budget validation vote, where voters approved a $46.2 million spending plan 2,721 to 1,413. The budget increases district spending by 1.5 p…