PR #372392 added runtime dependencies on the libevdev and pyudev python
packages, which are necessary to run several scripts contained in the
libwacom project. Since the project used a split derivation containing
`"out"` and `"dev"` outputs, this changed introduced python3 to the
closure of libwacom and all dependent packages.
By adding an additional `"bin"` output, the scripts will be contained
only in the `libwacom-bin` and `libwacom-out` closures. The `libwacom`
derivation does not depend on python.
```
$ nix-store -qR $(nix-build -A libwacom.out)
/nix/store/6h39qxzrm4i1fhl538knvyjapcdyasfx-xgcc-15.2.0-libgcc
/nix/store/hlcdbvwjlzjd2x86fxghzj1gpzplccqw-libunistring-1.4.1
/nix/store/kywwgk85nl83mpf10av3bvm2khdlq5ib-libidn2-2.3.8
/nix/store/j193mfi0f921y0kfs8vjc1znnr45ispv-glibc-2.40-66
/nix/store/1z031fwbsc8jhmm7i39r6z6m1xn7rbza-libffi-3.5.2
/nix/store/5qzr2w5n5gcgh8gp3mi8sdfh6ryypfqj-libxcrypt-4.5.2
/nix/store/jggxi5a991sx5si6sv47y0l2y1nqlh0g-pcre2-10.46
/nix/store/9862zy8hnb7xhygn1dbs9i316ldvbjyx-libselinux-3.8.1
/nix/store/c2qsgf2832zi4n29gfkqgkjpvmbmxam6-zlib-1.3.1
/nix/store/xbydf9b2lx6jziwi6z85g0bny5331dim-util-linux-minimal-2.41.2-lib
/nix/store/f7rcazhd826xlcz43il4vafv28888cgj-glib-2.86.3
/nix/store/dj62xc7d90axna889yzxd4r192vib8gj-util-linux-minimal-2.41.2-login
/nix/store/mm6518pcn7aggvsqzlag9awqacd88lm9-libcap-2.77-lib
/nix/store/n234iswy40dzhd7aw6ak0wfrbyjpvbw4-systemd-minimal-libs-258.2
/nix/store/n5zsk9wihymdwi7zss8d8my2m3njz1mp-libgudev-238
/nix/store/w3vy3bpndpj0b6ja5bgc7ll3kf5mv0qd-libevdev-1.13.4
/nix/store/cwdn4md7x08y7hjvlhz508zhnaxxsf1p-libwacom-2.17.0
```
