Update outdated golden tanuki logo

What does this MR do and why?

Update logo in ultimate trial banner and active trial status widget to be in-line with current brand guidelines

Screenshots or screen recordings

Before	After

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
• Register new user.
• Create new group. Visit root path.
• Validate trial banner logo.

bin/rails console

> GitlabSubscription
  .find_or_initialize_by(namespace: Group.last)
  .update(trial: true, trial_starts_on: Date.yesterday, trial_ends_on: 30.days.from_now, hosted_plan: Plan.find_by(name: 'ultimate'))

• Visit create group path.
• Validate trial widget logo.

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 #431132