Remove `coverage` build script
Remove `coverage` build script

The `test` Makefile target contains this logic.

edx/xblock-sdk,stvstnfrd/xblock-sdk,stvstnfrd/xblock-sdk,Lyla-Fischer/xblock-sdk,Lyla-Fischer/xblock-sdk,Lyla-Fischer/xblock-sdk,stvstnfrd/xblock-sdk,edx/xblock-sdk,edx/xblock-sdk