Demo Performance Fixes

Fixed a major memory leak caused by previous enemy buff optimizations. If you were having issues at Depth 600+, this may provide significant relief. Let me know how things go! Big thanks to TrebliF for helping diagnose this

Fixed one crash on exit

Optimized a few things around skill usage

Optimized a few combat calculations to not allocate additional memory needlessly

Fixed one case of Blade Toss and Kinetic Blades accidentally sharing an upgrade