Bundler 4.0.0 removed deprecated `--path` argument

[chhtz]

On Ubuntu 24.04 (or probably anywhere with ruby>=3.0) one now gets an error like this during bootstrapping (or autoproj update in existing workspaces):

The `--path` flag has been removed because it relied on being remembered across bundler invocations, which bundler no longer does. Instead please use `bundle
config set bin '/WORKSPACE/.autoproj/bin'`, and stop using this flag
autoproj_bootstrap:506:in `run_bundler': FAILED: bundler binstubs, --all, --force, --path, /WORKSPACE/.autoproj/bin in /WORKSPACE/.autoproj (Autoproj::Ops::Install::BundlerFailed)
	from autoproj_bootstrap:480:in `install_autoproj'
	from autoproj_bootstrap:754:in `install'
	from autoproj_bootstrap:824:in `stage1'
	from autoproj_bootstrap:873:in `<main>'

The quickest workaround is probably to fix the bundler version to 2.7.2, e.g. during bootstrap:

ruby autoproj_bootstrap --bundler-version="2.7.2" git $REPOSITORY_URL

This could be set in autoproj as well, similar to this: #402

But longtime, it would be nice to follow the recommended API of bundler.

[pierrewillenbrockdfki]

--path etc. have already been discouraged in bundler 2.1.4, announcing things to change with bundler 3, according to the manpage:

       Flags passed to bundle install or the Bundler runtime, such as --path foo or --without
       production,  are  remembered  between commands and saved to your local application´s
       configuration (normally, ./.bundle/config).

       However,  this  will  be  changed in bundler 3, so it´s better not to rely on this
       behavior. If these options must be remembered, it´s better to set them using
       bundle config (e.g., bundle config set path foo).

bundler 2.1.4 is present in ubuntu 20.04, but i think autoproj is already pulling the latest version anyway, ignoring the os-bundler, judging from bundler not being installed as os-package in my 18.04 VM.

I think it is safe to just update autoproj to use the "new" API.

[pierrewillenbrockdfki]

Made a draft PR #425

[chhtz]

@doudou or @g-arjones can you have a look at Pierre's PR or set the default bundler version to 2.7.2 for Ruby >=3.0?

[chhtz]

Should be fixed by #425. I'll close this when the next release gets out.