[Makefile] Fix trace target for when transcript not available
The file hardware/build/transcript is generated by ModelSim simulations only; when the target `make trace` is run after a Verilator simulation, transcript is not there and the recipe failed prior to this fix
@@ -215,7 +215,7 @@ pre_trace:
post_trace:
mkdir -p "$(result_dir)"
- cp $(buildpath)/transcript "$(result_dir)/"
+ cp $(buildpath)/transcript "$(result_dir)/" | true
cp $(traceresult) "$(result_dir)"
cp $(trace) "$(result_dir)"
