test: [DI-30016] - Add spec for Edit notification channel

[shnagend-akamai]

Description 📝

This PR introduces a new test specification for editing a notification channel in the Linode Manager application. It covers updating the channel name and modifying the list of recipients.

Changes 🔄

• Adds a test spec file to cover the "Edit notification channel" functionality.
• Includes UI test scripts to automate the workflow of editing a notification channel via the application interface.
• Corresponding API intercepts have been added to mock scenarios.
• The new specs ensure that notifications channels can be edited successfully, and that UI and backend behaviors are as expected.

Target release date 🗓️

Upcoming release

Preview 📷

alert-notification-channel-edit.spec.ts.mp4

How to test 🧪

pnpm cy:run -s "cypress/e2e/core/cloudpulse/alert-notification-channel-edit.spec.ts"

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