Exclude expired trial groups from tier badge experiment

What does this MR do and why?

Exclude the namespaces that have trialed in the past but are now free from the candidate experience. This could either be accomplished via a GLEX exclusion or an exclusion outside of GLEX.

We should aim for excluding via GLEX so that we don't track them at all for this exclusion

Screenshots or screen recordings

free group	free group with expired trial

How to set up and validate locally

• Setup gdk to simulate SaaS - https://docs.gitlab.com/ee/development/ee_features.html#simulate-a-saas-instance and restart GDK

bin/rails c

Feature.enable(:tier_badge)

• Sign in. Create group. Visit group page.
• Make sure group has tier badge popup.
• Create subgroup. Visit group page.
• Make sure group has no tier badge popup.
• Create new parent group. Visit group page.

bin/rails c

GitlabSubscription.find_or_initialize_by(namespace: Group.last).update(trial_ends_on: Date.yesterday)

• Reload page. Make sure group has no tier badge popup.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #418962 (closed)