On ZFS `copy_file_range()` and `sendfile()` fail for some reason, so add `EINVAL` to the list of error codes for which the code will fall back to a slower implementation.
While we are at it, add all the error codes from https://go.dev/src/internal/poll/copy_file_range_linux.go for different filesystems and older kernel versions to the list of error codes from `copy_file_range()`.
Without this, the cache defragmentation and the test testing it (`test_disk_cache`) fail with the error message "Failed to copy data to new disk cache file during defrag: Invalid argument" when the cache directory is stored on ZFS.
Perhaps this is caused by me running ZFS 2.1.2 on Linux 5.16.0, which is not a supported combination. This ZFS version is only "compatible with 3.10 - 5.15 kernels" according to the release notes. Or maybe it's just not implemented.
To reproduce the problem, execute `KITTY_CACHE_DIRECTORY=/path/to/zfs python3 test.py` with `KITTY_CACHE_DIRECTORY` pointing to a directory on ZFS.
If `errno` is `EAGAIN`, the second if statement is never true and if `errno` is not `EAGAIN`, the function returns immediately, not checking the second if statement.
This commit fixes this.
A logically equivalent change would have been to simply swap the two if statements but I find this version to be more readable.
