remove condition to check for expereimental feature enable

[MuhammadMullah]

Description

This PR fixes the problem of sandbox menu item not seen by removing the if condition that checks for the experimental feature flag.

Closes #4367

Validation steps

1. Sign In
2. From the menu, click on Projects
3. From the list of projects click one of the projects
4. You should now see the Sandboxes menu item appear

Additional notes for the reviewer

1. This PR fixes the first point of Sandboxes: Some users can't see the sandboxes menu item #4367, I could not produce the second behaviour listed in the issue.

AI Usage

Please disclose whether you've used AI anywhere in this PR (it's cool, we just
want to know!):

• I have used Claude Code
• I have used another model
• I have not used AI

You can read more details in our
Responsible AI Policy

Pre-submission checklist

• I have performed an AI review of my code (we recommend using /review
  with Claude Code)
• I have implemented and tested all related authorization policies.
  (e.g., :owner, :admin, :editor, :viewer)
• I have updated the changelog.
• I have ticked a box in "AI usage" in this PR

[josephjclark]

thank you @MuhammadMullah! We'll give this a close look

We might hold the PR open until we're absolutely ready to release this to all users - but the plan is to do this soon so it really won't be long :)