fix: [UIE: 10232] - Show the Blackwell Limited Availability Banner only for Blackwell Enabled customers

[harsh-akamai]

Description 📝

This PR fixes the visibility for Blackwell Limited Availability Banner so that it is displayed only to customers who have access to Blackwell GPUs and when Blackwell plans are unavailable in the selected region

Changes 🔄

• In PR #13408 the check for showing the limited availability banner doesn't cover the scenario when a user doesn't have access to Blackwell plans

Scope 🚢

Upon production release, changes in this PR will be visible to:

• All customers
• Some customers (e.g. in Beta or Limited Availability)
• No customers / Not applicable

Target release date 🗓️

19 Feb

Preview 📷

Before(Without Blackwell access)	After(Without Blackwell Access)
Before(With Blackwell access)	After(With Blackwell Access)
-------	-------

How to test 🧪

Reproduction steps

• Remove the blackwell tag from your admin account
• Navigate to the Linode Create page
• Select a region and navigate to the GPU tab
• You should be able to see the Blackwell Limited Availability Banner(not to be seen ideally)

Verification steps

(How to verify changes)

• Ensure that your Linode account doesn't have access to Blackwell plans
• Verify that you do not see the Blackwell Limited Availability Banner when you select a region the Linode Create page
• Add the blackwell tag back to your account
• Verify that you only see the banner when the Blackwell gpus are unavailable in the selected Location

Author Checklists

As an Author, to speed up the review process, I considered 🤔

👀 Doing a self review
❔ Our contribution guidelines
🤏 Splitting feature into small PRs
➕ Adding a changeset
🧪 Providing/improving test coverage
🔐 Removing all sensitive information from the code and PR description
🚩 Using a feature flag to protect the release
👣 Providing comprehensive reproduction steps
📑 Providing or updating our documentation
🕛 Scheduling a pair reviewing session
📱 Providing mobile support
♿ Providing accessibility support

• I have read and considered all applicable items listed above.

As an Author, before moving this PR from Draft to Open, I confirmed ✅

• All tests and CI checks are passing
• TypeScript compilation succeeded without errors
• Code passes all linting rules

[grevanak-akamai]

Nit: instead of blackwellGpuPlans && blackwellGpuPlans?.length, blackwellGpuPlans?.length is sufficient.

[linode-gh-bot]

Cloud Manager UI test results

🎉 868 passing tests on test run #4 ↗︎

❌ Failing	✅ Passing	↪️ Skipped	🕐 Duration
0 Failing	868 Passing	11 Skipped	37m 40s