Is my nearby neighbor's foundation excavation a concern for my home?
This is a common situation and is extremely unlikely to cause significant damage to your house. The biggest risks are (a) that someone is exceptionally sloppy and damages your  services (water/sewer/gas/electric) while digging to install the new services, and (B) vibration might provoke a bit of minor settling and a crack or two in your  plaster.

Disasters aren't impossible, but also aren't worth worrying about until they occur, unless there is something very, very odd about your situation. And if a disaster should occur, the builder's insurance should cover it, if they are at all legitimate.