bug#80339: [9.10] tests/misc/usage_vs_refs fails with kill and uptime enabled

Hi,

It looks like a doctest fails when providing `configure` the
`--enable-install-program=kill,uptime` flag (per NEWS for v9.10).

```
> ./configure --enable-install-program=kill,uptime
...
> make -j
...
> make -j check
...
FAIL: tests/misc/usage_vs_refs
==============================

kill -s reference missing in texi
kill --signal reference missing in texi
kill -SIGNAL reference missing in texi
kill -l reference missing in texi
kill --list reference missing in texi
kill --table reference missing in texi
FAIL tests/misc/usage_vs_refs.sh (exit status: 1)
...
```

This occurs on Debian and NixOS, both on x86_64 using WSL.
I haven't tested on any other platforms.

I've attached test_suite.log (tarred and gzipped).

Best,
Michael Daniels