also cleanup old unused versions

nodejs 8 does not seem to support higher version.

/reviewed-on nexedi/slapos!461

https://github.com/v8/v8/wiki/Building%20with%20Gyp

The build of nodejs uses python, and python leaking from the system can lead
to unexpected results, thus use provided from SlapOS.

/reviewed-on !319

This nodejs version needs python in $PATH for the build. During build,
it will build `icupkg` without honoring $LDFLAGS, so our rpath does not
work and this icupkg does not find it's libssl. To prevent it from using
system libssl, run the build step under $LD_LIBRARY_PATH

Known nodejs bug[1] has proposed fix [2] applied directly here.

[1] https://github.com/nodejs/node/issues/9137
[2] https://github.com/riedonetworks/meta-nodejs/commits/dora/recipes/nodejs/files/0001-fix-execvp-printf-argument-list-too-long.patch

Won't create /opt/slapgrid/.npm anymore