Merge pull request #5560 from RosettaCommons/roccomoretti/EnergyMap_array
Convert EnergyMap to use a std::array.
This is based off of PR #5556, and the hope is that the std::array will get around the GCC 11 errors that are seen with the copy constructor/assignment operator. (Mostly because we can defer the copy/assignment operations to the std::array versions.)
This PR also removes the -fno-builtin flag from the GCC 11 compilation, which was previously added in PR #5552 as a workaround for the issue that this PR fixes.