AT&T is moving customers off older copper phone lines and onto newer technology, and for longtime landline users, that shift may already be underway.The FCC has granted AT&T permission to wind down most of its copper network in 18 by the end of 2029.An AT&T customer in Tennessee brought the issue to light after the company told them their damaged home phone line would be upgraded rather than repaired, citing the line's age and repair costs. The …