Auto merge of #6601 - deivid-rodriguez:more_flexible_stub, r=segiddins
Auto merge of #6601 - deivid-rodriguez:more_flexible_stub, r=segiddins

More flexible stub

### What was the end-user problem that led to this PR?

My problem is that I can't get https://github.com/rubygems/rubygems/pull/2332 CI passing.

### What was your diagnosis of the problem?

My diagnosis was that current bundler test don't support my changes in that PR, because previously the `validate` method in `rubygems` would be called without arguments, and now it's called with two arguments.

### What is your fix for the problem, implemented in this PR?

My fix is to make the specification stub more flexible so it supports any number of arguments.

### Why did you choose this fix out of the possible options?

I chose this fix because it supports my changes and doesn't break the previous version either.

(cherry picked from commit b8fdc4ae2318369a7cd71eabcdc611162fa2fee6)

mvz/bundler,dilumnavanjana/bundler,bundler/bundler,dilumnavanjana/bundler,mvz/bundler,bundler/bundler