Update struct_smart_holder.h

Author: henryiii

include/pybind11/detail/struct_smart_holder.h

@@ -59,10 +59,10 @@ High-level aspects:
 #include <utility>
 
 // IMPORTANT: This code block must stay BELOW the #include <stdexcept> above.
-// This is only requried on some builds with libc++ (one of three implementations
+// This is only required on some builds with libc++ (one of three implementations
 // in
 // https://github.com/llvm/llvm-project/blob/a9b64bb3180dab6d28bf800a641f9a9ad54d2c0c/libcxx/include/typeinfo#L271-L276
-// requiere it)
+// require it)
 #if !defined(PYBIND11_EXPORT_GUARDED_DELETE)
 #    if defined(_LIBCPP_VERSION) && !defined(WIN32) && !defined(_WIN32)
 #        define PYBIND11_EXPORT_GUARDED_DELETE __attribute__((visibility("default")))