cat: don’t treat copy_file_range EFBIG as fatal

cat: don’t treat copy_file_range EFBIG as fatal

* src/cat.c (copy_cat):
* src/copy-file-data.c (sparse_copy):
Don’t treat EFBIG as a reportable error from copy_file_range.
If the input is at EOF and the output position is 2**63 - 1,
copy_file_range (ifd, NULL, ofd, NULL, 2146435072, 0)
incorrectly fails with EFBIG.  Problem observed on Ubuntu 25.10
x86-64 with Linux kernel 6.17.0-8-generic #8-Ubuntu.
I am too lazy to report this kernel bug or add a coreutils test case.