lcs: add build patch for newer clang

[chenrui333]

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  In file included from ./includes.h:215:
  ./cursesgraphics.h:1706:49: error: non-constant-expression cannot be narrowed from type 'chtype' (aka 'unsigned int') to 'int' in initializer list [-Wc++11-narrowing]
   1706 | {                                               CH_UNIT_SEPARATOR,     31,},
        |                                                 ^~~~~~~~~~~~~~~~~

https://github.com/Homebrew/homebrew-core/actions/runs/10861349377/job/30143141027#step:4:658