have the dependents test test all dependents

[wchristian]

Fixed this up to run relatively fast (about 12 minutes). Two issues that remain:

• the "install extra modules" step could probably be cached? @haarg, olaf mentioned you as someone who might know how?
• the failing test themselves aren't output. gonna need to debug that and see how the test module can be made to do that, because the docs don't say

[wchristian]

Ran the action against the previous version, and there only Devel::Examine::Subs failed, which might have more to do with the environment than PPI changing. Otherwise only Perl::Critic fails, which has a PR fix from me.

[oalders]

@wchristian just wondering why you closed this?

[wchristian]

@oalders correcting my previous statement: the pull request was closed because the code in question is done and merged, however the bigger issue is still in question in #297