Fix clang errors "different exception specifier" (regr. 2023-09-04). * lib/malloc.in.h (memalign): Don't use _GL_ATTRIBUTE_NOTHROW on platforms other than glibc systems. * lib/stdio.in.h (fdopen): Likewise. * lib/stdlib.in.h (aligned_alloc, calloc, canonicalize_file_name, malloc, realloc): Likewise. * lib/string.in.h (strdup, strndup): Likewise. * lib/sys_stat.in.h (getumask): Likewise. * lib/wchar.in.h (wcsdup): Likewise.