Ruby

Remove unnecessary prototype declarations

internal/class.h:158:20: warning: ‘RCLASS_SET_CLASSEXT_TABLE’ declared ‘static’ but never defined [-Wunused-function] 158 | static inline void RCLASS_SET_CLASSEXT_TABLE(VALUE obj, st_table *tbl); | ^~~~~~~~~~~~~~~~~~~~~~~~~ internal/class.h:271:20: warning: ‘RCLASS_WRITE_SUBCLASSES’ declared ‘static’ but never defined [-Wunused-function] 271 | static inline void RCLASS_WRITE_SUBCLASSES(VALUE klass, rb_subclass_anchor_t *anchor); | ^~~~~~~~~~~~~~~~~~~~~~~