Fix "cannot load such file -- zeitwerk (LoadError)" during VSCode Task

What does this merge request do and why?

Fix cannot load such file -- zeitwerk (LoadError) during the Bootstrap GDK VSCode Task, which runs every time you open the GDK directory in VSCode.

I attempted to add bundle exec like:

  "command": "bundle",
  "args": ["exec"],

But it still didn't work. By chance, I deleted "type": "shell" and it worked.

This works for me locally but I have no idea what impact it has in other contexts (like remote development)

Before

 *  Executing task: support/gitlab-remote-development/setup_workspace.rb 

/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require': cannot load such file -- zeitwerk (LoadError)
        from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
        from /Users/mkozonogitlab/Developer/gdk/lib/gdk.rb:12:in `<top (required)>'
        from support/gitlab-remote-development/setup_workspace.rb:6:in `require_relative'
        from support/gitlab-remote-development/setup_workspace.rb:6:in `<main>'

 *  The terminal process "/bin/zsh '-l', '-c', 'support/gitlab-remote-development/setup_workspace.rb'" terminated with exit code: 1. 
 *  Terminal will be reused by tasks, press any key to close it. 

After

 *  Executing task: support/gitlab-remote-development/setup_workspace.rb  

ℹ️  Nothing to do as we're not a GitLab Workspace.

 *  Terminal will be reused by tasks, press any key to close it. 

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

Impacted categories

The following categories relate to this merge request:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.

Merge request checklist

• This change is backward compatible. If not, please include steps to communicate to our users.
• [-] Tests added for new functionality. If not, please raise an issue to follow-up.
• Documentation added/updated, if needed.
• [-] Announcement added, if change is notable.
• [-] gdk doctor test added, if needed.
• [-] Add the ~highlight label if this MR should be included in the CHANGELOG.md.