Remove unused declaration of type `nodesizefn_t`
Remove unused declaration of type `nodesizefn_t`

This type was declared in lib/common/render.h, but never used.

ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz