Redo: Run Bundler v1 helpers with explicit version

[feelepxyz]

This brings back this revert: #3222

Work in progress to figure out how to run multiple bundler version

[brrygrdn]

Test failures aside, I think using Bundler's own environment management is a step in the right direction, I've been able to get a sensible outcome across the three test repos along with our specific git-dependency test https://github.com/dsp-testing/bundler1-git-test

bin/dry-run.rb bundler dsp-testing/bundler1-git-test

=== byebug (fead41cb53d349e11045a05cc804740089dbfa80)
 => checking for updates 1/2
 => latest available version is 11.1.3
 => latest allowed version is 11.1.3
 => requirements to unlock: own
 => requirements update strategy: bump_versions
 => updating byebug from fead41cb53d349e11045a05cc804740089dbfa80 to 11.1.3
    ± Gemfile
    ~~~
    3c3
    < gem "byebug", git: "git@github.com:deivid-rodriguez/byebug.git", ref: "v11.1.0"
    ---
    > gem "byebug"
    ~~~
    ± Gemfile.lock
    ~~~
    1,7d0
    < GIT
    <   remote: git@github.com:deivid-rodriguez/byebug.git
    <   revision: fead41cb53d349e11045a05cc804740089dbfa80
    <   ref: v11.1.0
    <   specs:
    <     byebug (11.1.0)
    <
    11a5
    >     byebug (11.1.3)
    18c12
    <   byebug!
    ---
    >   byebug
    ~~~

[feelepxyz]

Changed this to match BUNDLE_GEMFILE but not sure it's necessary, both seemed to work inside and outside the container with v1 and v2 installed

[brrygrdn]

As discussed synchronously, I'm 👍🏻 on having versioned_helper_path(bundler_version: bundler_version) as a clean(ish) room bundler path for all things related to the native helper process.

[brrygrdn]

Pending some further testing, I think this is ready to 🚢 🎉

Since it took a lot of iterations to get this working end to end, how do you feel about squashing the commit history for merge?

[brrygrdn]

🚀

[feelepxyz]

This is required when running with bundler 2 installed alongside v1, without this it defaults to v2 during dry-runs.

[brrygrdn]

As discussed synchronously, the use of Find in these gemspecs is atypical and not suggested by Bundler v1.17.x or v2.x.x when generating new gems.

Since Find isn't in the ruby context by default, we'd expect .gemspecs in the real world to have this require