[CodeGen] Remove extraneous casts to VariableID (NFC)#145144

kazutakahirata merged 1 commit intollvm:mainllvm/llvm-project:mainfrom

kazutakahirata:cleanup_20250620_static_cast_VariableIDkazutakahirata/llvm-project:cleanup_20250620_static_cast_VariableIDCopy head branch name to clipboard