Support gems installed from git source

[maxirmx]

If tebako package includes a gem installed from git source the package application fails.
Normally it can run using bundle exec

require 'bundler'
Bundler.require(:default)

the error message is

/__tebako_memfs__/lib/ruby/3.1.0/bundler/source/git/git_proxy.rb:224:in `allowed_with_path': The git source https://github.com/metanorma/vectory.git is not yet checked out. Please run `bundle install` before trying to start your application (Bundler::GitError)

although git cache is present inside memfs