PhantomJS isn't maintained anymore. It was an headless WebKit browser used for testing, generate screenshot of websites, etc.
Meanwhile, Firefox and Chromium both provides headless version.
According D1382 / b3ef1c3792, it was installed for a Foundation blank template, but this template doesn't require phantomjs anymore.
----------
ID: devserver_software_dev_web
Function: pkg.installed
Result: False
Comment: Problem encountered installing package(s). Additional info follows:
errors:
- pkg: No packages available to install matching 'phantomjs' have been found in the repositories
Started: 19:54:41.817974
Duration: 1113.806 ms
Changes:
...