Lab 1a: build.sbt prevents chipyard build

[GottaGetPaid]

Summary: Got through lab 1a until ./build-setup.sh riscv-tools -s 6 -s 7 -s 8 -s 9 -s 10 --use-lean-conda errors out.

Environment: Working on eda-4.

Fix: comment out all lines in build.sbt until we need it later.