When bundler specs are run from a ruby tarball (ruby-core does this),
there's no git folder, so `git ls-files` fails.

Support this case by making specs rely on the list of files from the
bundler gemspec instead, and invert the spec that makes sure we ship the
right set of files.

As per the other quality specs, skip them in this case.

https://github.com/rubygems/rubygems/commit/b28d5ec931

https://github.com/rubygems/rubygems/commit/1cc02930f3

This reverts commit 67d2a715ca35090fbb3ab13df5b7348b1807dd47.

https://github.com/ruby/actions/runs/703745101?check_suite_focus=true#step:16:27
```
An error occurred in a `before(:suite)` hook.
Failure/Error: contents = File.read(version_file)

Errno::ENOENT:
  No such file or directory @ rb_sysopen - /home/runner/work/actions/actions/snapshot-master/tmp/1/bundler-2.2.0.dev/lib/bundler/version.rb
```

ref 9aa75795f9f438d5c874d8e418c3c7cdd63024fa